Glossary A to Z

0-9, ABCD, E, F, G, H, I, J, K, L, M, N, O, P, Q, R, S, T, U, V, W, X, Y, Z



4 P

Refers to a pyramid with four layers describing the Toyota Way:

  1. Philosophy
  2. Process
  3. People and Partners
  4. Problem Solving.


References: Liker, J.K. (2003). The Toyota Way: 14 Management Principles from the World's Greatest Manufacturer. McGraw-Hill, 362 pp. Liker, J.K. and Meier, D. (2005). The Toyota Way Fieldbook: A Practical Guide for Implementing Toyota’s 4Ps. New York: McGraw-Hill, 476 pp.

5 Big Ideas

→ see Five Big Ideas

5 S

A disciplined approach to maintaining order in the workplace, using visual controls, to avoid and eliminate waste. English translations from Japanese of the 5 S words are:

  1. Sort
  2. Straighten or Set in Order
  3. Shine or Sweep
  4. Standardize
  5. Sustain or Self-Discipline.

5 WHYs, 5 Why analysis

A problem solving technique based on asking why successively (at least 5 times) in order to get beyond the symptoms of a problem and to uncover the root cause. Reference: For a definition, also see p. 17 in Ohno, T. (1988). The Toyota Production System: Beyond Large-Scale Production. Productivity Press, Portland, OR, 143 pp.

7 wastes

Ohno (1988) defined seven wastes in production:

  1. Defects
  2. Inventory
  3. Processing or Over Processing
  4. Waiting
  5. Motion
  6. Transportation or Conveyance
  7. Overproduction

Womack added

  • Not using people's capabilities

Koskela (2004) added

  • Make-do

→ related to Muda

Koskela, L. (2004). “Making-do: the Eighth Category of Waste.” In: Bertelsen, S. and Formoso, C.T., Proc. 12th Annual Conference of the International Group for Lean Construction, Helsingør, Denmark, 3-5 Aug.
Ohno, T. (1988). The Toyota Production System: Beyond Large-Scale Production. Productivity Press, Portland, OR, 143 p.




A3, A3 thinking

A report prepared on a single sheet of paper (size 297 mm × 420 mm or approximately 11” x 17”) that adheres to the discipline of PDCA thinking as applied to problem solving that is called “A3 thinking.”

The problem solving A3 includes the background, problem statement, analysis, proposed corrective actions (and the action plan), and the expected results, often with graphics. A3 reports can be used as a standard method for summarizing problem solving efforts (e.g., analysis of Target Value Design options), status reports, and planning exercises.

Reference: Shook, J. (2008). Managing to Learn: Using the A3 Management Process to Solve Problems, Gain Agreement, Mentor and Lead. Lean Enterprise Institute, Boston, MA.



How close the actual value of a quantity is to its specification (as distinct from precision).

→ related to predictability

Example: The painter’s duration estimate of 7 days plus-or-minus 2 days was accurate though not very precise: it took 8.5 days.


action research

Research that follows a progression of PDCA cycles while engaging in real world processes (rather than conducting isolated laboratory experiments).

G_action research cycle

Source: Action research cycle (adapted by Iris Tommelein from image posted on

The process starts with defining the issue by conducting initial observations and collecting existing data, then planning an intervention, then intervening, and ultimately analyzing and reflecting on that intervention as well as reporting out; it gets repeated over and over.



The taking of an action.

In the context of production management, action is taken in order to achieve an end such as achieving a recognizable state of completion or meeting a condition of satisfaction (as opposed, e.g., to reacting to some occurrence).

Activity is a general term used to avoid the specificity of, for example, use of the word task or step for example in the Last Planner System.


Activity Definition Model (ADM)

An input-process-output representation of work to be done in design or construction. The model depicts the specification of directives (entering the process rectangle from above), prerequisites (including materials and information to be transformed into the desired output, entering the process rectangle from the left), and resources (entering the process rectangle from below). It also shows an inspection process resulting either in redo or release to the customer process. The model is used as a guide to exploding scheduled tasks into a level of detail at which their readiness for execution can be assessed and advanced.


Image source: Jerry Talley


activity-on-arrow diagram (AOA)

Network drawn to support computations using PERT. It shows activities as arrows, delimited by event nodes.

This notation convention is the inverse of the activity-on-node diagram that is used in the Critical Path Method (CPM).


activity-on-node diagram (AON)

Network drawn to support computations using the Critical Path Method (CPM). It shows activities by means of nodes and precedence relationships by means of arrows.

This notation convention is the inverse of the activity-on-arrow diagram that is used in PERT.


Actual Cost (AC) [TVD]

The documented amount of money spent to actually perform work (an activity, chunk of work, or an entire project) based on the agreed definitions of cost, overhead, and profit.



→ see Activity Definition Model


advantage [CBA]

In the context of Choosing by Advantages, an advantage is the beneficial difference between attributes of two alternatives, one of which is the least preferred when assessed according to a certain criterion (after Suhr 1999).


Allowable Cost (AC) [TVD]

In Target Value Design, what an owner is willing and able to pay in order to get what they want, in other words, what that product or asset is worth to them.


alternative [CBA]

In the context of Choosing by Advantages, two or more people, things, or plans from which one is to be chosen (Suhr 1999).


anchoring [CBA]

In the context of Choosing by Advantages, the practice of basing decisions, attributes, and importance on (anchored to) relevant factual data (Suhr 1999).



Signal given by a production unit to alert others of the occurrence of a deviation from the standard and to possibly call for immediate help so that a countermeasure can be implemented without exceeding the Takt time and having to stop the assembly line.


Assembled To Order (ATO)

Product put together from parts that are already designed and made so as to meet the specifics of a customer request (order).

One category in a classification that distinguishes how long a product or service remains generic vs. becomes customer specific in its production.

One approach for mass customization, whereby parts may have been produced in volume based on forecast.

→ related to ETO, FTO, MTO, MTS, and CODP


Source: Iris D. Tommelein


assignment [LPS]

A request made to and accepted by a worker or workers (production unit) directly or indirectly producing (designing and making) something or offering a service.

In the Last Planner System, a request or offer that meets the quality criteria and has resulted in a reliable promise, ready to be placed on the Weekly Work Plan for performance.
Example: Scott, you and Julie are to make the changes in wall locations detailed in memo #123 by the end of the week. Anne, you find out what the building authorities will require for a structural permit.



→ see Assembled To Order


attribute [CBA]

In the context of Choosing by Advantages, a characteristic, quantity, or quality of one alternative (Suhr 1999).



“Intelligent automation” or “automation with a human touch” whereby a machine is made not only to fulfill its production function, but also to perform quality control functions, namely detect defects and automatically stop.

Autonomation helps to implement the jidoka principle (and pillar) in the Toyota Production System.





In planning →  see workable backlog


backward pass calculation [CPM]

Calculation of the late finish date and late start date of an activity in a network, taking into account the activity precedence relationships, by starting from the end of the schedule.


(to) balance

Matching load to capacity. Matching demand with supply.



The number of units that are being worked on simultaneously before a process produces output (production batch) or the number of units that together are being handed off from one production unit to the next (transfer batch).

A goal of lean is to achieve single-piece flow, that is, use batches of size 1 (1 being the unit the customer wants).


(to) batch

The practice of creating a batch or batches.


batch flow

Production system whereby processing stations (machines) are laid out by functional grouping so that each unit being produced is likely to have to follow a jumbled flow from one to the next, according to the processing steps it requires.

G_batch flow

Figure source: Schmenner (1993)

Reference: Schmenner, R. W. (1993). Production/operations management: from the inside out. Macmillan College.


Big Room, Oba, Obeeya

A designated place for a team to co-locate, engage in collaborative problem solving, and maintain a visual workplace.



→ see Building Information Model(-ing)



→  see Built-in Quality



The production unit with the lowest throughput (longest cycle time) of all production units in a system (the choke point) that is linear, sequential, and deterministic.

In other systems, bottlenecks also exist but they may be harder to pinpoint. Moreover, due to the possible inter-relatedness of parts and dynamic, stochastic characteristics of a system, its bottleneck(s) may shift over time.



Deviation from standard process or target outcome(s).

Types of breakdowns:

  1. Near misses, accidents, injuries
  2. Errors, defects, rework
  3. Broken promises, plan failures

Breakdowns provide learning opportunities because either

  1. we did not properly perform process A and need to learn how to do so, or
  2. our knowledge regarding causality “IF A THEN B” is inadequate.

broken promise → also see reliable promise

plan failure → also see quality criteria [LPS]



A mechanism for deadening the force of a concussion; e.g., a capacity buffer is created by scheduling less than all the time available (aka. underloading the production unit or other resource). If production falls behind schedule, there is capacity available for catching up. Capacity buffers may be preferred over inventory buffers. In addition to capacity and inventory buffers, other types of buffers are time buffers, monetary buffers (contingency), and spatial buffers (tolerances or allowable dimensional variation). Arguably, monetary buffers can be converted into, e.g., capacity buffers or inventory buffers.

A decoupling buffer is a kind of inventory buffer in-between two processes, large enough and replenished so that the second process can proceed at its own pace without being held up by the first.


buffer management

The selection, location, and sizing of buffer types within a production system in order to absorb variations in that system. It can include the modification of one or several of those selections as the project moves through time.

For example, buffers may be constrained (limited to a maximum size) by implementing pull using kanban or CONWIP.


Building Information Model(-ing) (BIM)

The process of generating and managing building data during the life cycle of a building.

The system comprising an integrated database, one output of which is a 3-dimensional model. 3D BIM refers to the 3-dimensional geometrical model, including spatial relationships, geographic information, and non-spatial properties of building components and systems. 4D also includes time so it may allow for simulation of the building assembly process. 5D further includes cost data so it may allow for cost modeling. 6D refers to a BIM annotated with data so it may support facility life-cycle management.


Built-in Quality (BiQ)

Quality achieved by work structuring, including designing operations so as to meet customer requirements, removing constraints, preparing workers, mistakeproofing and performing successive inspection during each processing step, as well as at each handoff; i.e., designing and executing the processes of making things so those products conform to requirements.
BiQ aims to avoid the reliance on end-of-line inspection and correction to achieve conformance to requirements.

G_BiQ process 2016-01-19

Figure source: (c) 2015, Iris D. Tommelein



[units of work/unit of time] The amount of work a production unit, whether individual or group or a machine, can accomplish in a given amount of time in given conditions.

Example: Jim the engineer can perform 10 piping stress analyses per day on average, but the analyses to be done this week are particularly difficult. He will only be able to do 7. That is, Jim’s average capacity is 10, but his capacity for the specific work to be done this week is 7.

cause-and-effect diagram, fishbone diagram, Ishikawa diagram

Graphical representation of causes and effects laid out so as to mimic the bones of a fish. Named after Kaoru Ishikawa (1915-1989). G_cause-and-effect

Figure source: visited 6 NOV 2014


→ see Choosing by Advantages


CBA Process for Complex Decisions [CBA]

Decisionmaking process articulated by Jim Suhr (1999) comprising five phases:

I. The Stage-Setting Phase

II. The Innovation Phase

III. The Decisionmaking Phase

IV. The Reconsideration Phase

V. The Implementation Phase

Reference: Suhr, J. (1999). The Choosing By Advantages Decisionmaking System. Quorum, Westport, CT, 293 pp.


(to) change over, changeover

Setup or adjustment required to a process, machine, layout, etc. when one is done making one kind of product, in order to be able to start making another kind of product. → related to (production) batch

Choosing by Advantages [CBA]

System for sound decisionmaking formalized by Jim Suhr (1999).

Reference: Suhr, J. (1999). The Choosing By Advantages Decisionmaking System. Quorum, Westport, CT, 293 pp.


→ see Customer Order Decoupling Point

commitment plan [LPS]

Output of commitment planning. A Weekly Work Plan is a commitment plan done weekly. (Arguably, planning at any level involves making commitments.) → see reliable promise


commitment planning, commitment-based planning [LPS]

A planning system that is based on making and securing reliable promises in a public setting. The process in the planning system hierarchy, below make-ready planning (lookahead planning), that results in production units making commitments to deliver on which others in the production system can rely because they follow the rule that only defined, sound, sequenced and sized assignments are to be accepted or made. Commitment planning done on a daily/weekly basis is called Daily/Weekly Work Planning. Tasks in commitment plans are expressed in terms of steps in operations. The commitment is made to completing the operation.

Example: On my work plan for next week, I have included providing Cheryl the soils data she needs to evaluate alternative substructure systems for the building. All known constraints have been removed from my task, I understand what is required and how the information will be used, and I have reserved needed labor and equipment.

commodity material

Material made by different manufacturers but more-or-less indistinguishably from one to the other, thereby allowing for substitution or interchangeability. Also, material that is supplied and replenished in bulk quantity, for which no piecemeal quantity take-off is done.

Example: This box contains one pound of 3” wire nails.

Community of Practice (COP)

A group of people who share a concern or a passion for something they do and learn how to do it better as they interact regularly. Reference: Wenger-Trayner and Wenger-Trayner (2015). “Communities of practice: A brief introduction.” April 15,, Brief-introduction-to-communities-of-practice.pdf visited 10 JAN 2016.


Not simple, nor complicated. Snowden describes that in the complex domain, cause-effect relationships are not a priori known.

→ as distinct from simple or complicated

Reference: Snowden, D.J. and Boone, M.E. (2007). “A Leader’s Framework for Decision Making.” Harvard Business Review, Nov., 69-76.


Not simple, nor complex. Snowden describes that in the complicated domain, cause-effect relationships (1) exist, (2) there is a right answer, but it is not so self-evident and therefore requires expertise. One can use an analytical model or call in experts who built expertise in that domain, who can make the right decision. In the complicated domain, experts apply good practice (not best practice). There are several ways of doing things, all of which legitimate, if you have the right expertise. You’ll tick people off, by forcing them to adopt one practice, if they want to use another practice. → as distinct from simple or complex Reference: Snowden, D.J. and Boone, M.E. (2007). “A Leader’s Framework for Decision Making.” Harvard Business Review, Nov., 69-76.

Condition of Satisfaction (COS)

Directive (proactive: for steering) and criterion (reactive: for judging), imposed by the entity initiating a process (usually the customer) that specify (to the performer of that process) how success of the outcome will be gauged. What will make a customer satisfied with the service or product received.


An input, directive, resource, or other requirement that will prevent a task or an assignment from starting, advancing, or completing as planned.


constraint [CBA]

Cause for an alternative to be excluded from consideration. In the context of Choosing by Advantages, a must criterion or money.


constraint [LPS]

In the context of the Last Planner System, something that stands in the way of a task being executable or sound. Typical constraints on design tasks are inputs from others, clarity of requirements criteria for what is to be produced or provided, approvals or releases, and labor or equipment resources. Typical constraints on construction tasks are the completion of design or prerequisite work; availability of materials, information, and directives. Screening tasks for readiness is assessing the status of their constraints. Removing constraints is making a task ready to be assigned.


constraint log

A list of constraints, each one with an identification of the individual who promised to remove it by an agreed-upon date. The log gets developed during the make-ready process in lookahead planning. Each individual who promises to remove a constraint can manage their constraint removal process by using their own Last Planner System.


Synonym for buffer but typically used in the sense of “financial contingency.” Amount of money budgeted to function as buffer against un-specifiable future costs.

continuous improvement

Repetition of the PDCA cycle.

continuous flow, continuous flow process

Production system with processes that have no buffers in-between processing steps.

Illustration → see batch flow

G_continuous flow

Example: After the concrete has been placed and vibrated, it begins to cure.

(to) control

To engage in activities designed to cause events to conform to plan (i.e., to provide the ability to steer), or to initiate replanning and learning.

Example: Exploding master schedule activities into greater detail, screening the resultant tasks against constraints, and acting to remove those constraints are all control actions intended to cause events to conform to plan, or to identify as early as practical the need for replanning. Learning is initiated through analysis of reasons for failing to cause events to conform to plan.

controls, project controls

High-level set of metrics and practices applied to assess whether or not project’s execution is progressing as planned (that is, producing expected outcomes); often retrospective by nature.


CONstrained Work In Process. A means to limit the amount of inventory in a production system.


→ see Community of Practice


→ see Condition of Satisfaction

cost modeling

The practice of keeping track of component- and system costs in the course of design, as may be done by means of 5D BIM.


Corrective action taken in response to the identification of a deviation from an expected outcome in an attempt to prevent that problem from occurring. Whether or not that attempt is successful will have to bear out.


→ see Critical Path Method

crew balance chart

Depiction of workers or production units with the tasks they are performing over time. The aim is to determine each person’s (unit’s) utilization and to divide work evenly. Note: crew balancing aims are optimizing the crew speed. This is local optimization as no consideration is given to the handoffs between this crew and others nor to production system design in general. G_crew balance chart

References: Howell, G., Laufer, A., and Ballard, G. (1993). “Interaction between Subcycles: One Key to Improved Methods.” ASCE, J. Constr. Eng. Manage., 119 (4) 714-728.

Oglesby, C.H., Parker, H.W., and Howell, G.A. (1989). Productivity Improvement in Construction. McGraw-Hill.

→ see the broader concept Takt Planning


criterion (in plural: criteria) [CBA]

In the context of Choosing by Advantages, a criterion is any standard on which a judgment is based (Suhr 1999). A criterion can be either a must criterion or a want criterion.

  • Must Criterion: A standard that an alternative must meet or be excluded from consideration.
  • Want Criterion: A standard that the stakeholders agree would be beneficial in varying degrees (e.g., expressing a preference).

A criterion can be qualitative or quantitative:

  • Qualitative Criterion: A standard that expressed non-tangible value. It must be described in details that the stakeholders understand.
  • Quantitative Criterion: A standard that can be measured objectively.


criterion (in plural: criteria) [LPS]

In the context of the Last Planner System, criteria are a subset of directives, specifically those used to evaluate process outputs.

Critical Path Method (CPM)

A method for computing the shortest duration of a network of activities, based on a duration estimate (deterministic number) for each activity and precedence relationships between them (e.g., finish-to-start relationships). The sequence of activities that defines this shortest duration is called the ‘critical path.’

→ related to float, forward pass, backward pass.

cross-functional diagram, multi-functional diagram, swimlane diagram

Illustration of work to be done by each party or team (each one in a single row or “lane”) involved in process, and of relationships or hand-offs between them.

current state map [VSM]

A value stream map that describes the existing (current, observed) situation.


The direct or indirect user or beneficiary of one’s output. The person (production unit) who requests and sets the requirements for the handoff to be received from the performer. The individual engaged in a conversation for action who will receive the output or results of performance either requested from, or offered by, the performer. Example: John needs the results of our acoustical tests in order to select the best location for his mechanical equipment. John is our customer because he will use what we produce.

Customer Order Decoupling Point (CODP)

A point in the production system (supply chain) where requirements specific to an individual customer are applied to customize the product. At and downstream of that point, the product is therefore made based on demand. Upstream of that point, the product is made based on forecast. The location of the COPD affects the lead time. Illustration → see Assembled To Order → related to ETO, ATO, MTO, and MTS



Making a product or service more unique, specifically in order to meet a customer’s conditions of satisfaction.

Cycle Time (CT) ∆

[unit of time] The time it takes a product, piece of information, or chunk of work (e.g., a room, building, quadrant) to go from beginning to end of a production process; that is, the time it is work-in-process [units of time]. It is the time for a product to transit the system and thus defined by how one defines the boundaries for that system. The cycle time is influenced by a number of production system design parameters:

CT = BT + MT  + ST + PT + QT


BT = batch time MT = move time ST = setup or change over time PT = processing time QT = queue time

→ see work in process, Little’s Law, Kingman Formula


cycle time histogram [TP]

Synonym for Yamazumi chart or stacked bar chart.

see → stacked bar chart




decoupling buffer

→ see buffer



An output that does not conform to a condition of satisfaction or specification; not to standard; not of quality. One of 7 wastes defined by Ohno (1988) referring to effort needed to address incorrect information, rework, and scrap.


defined, definition [LPS]

In the Last Planner System, a quality criterion for assignments that questions whether or not assignments are specific enough so that the right type and amount of information and materials can be collected, work can be coordinated with other disciplines or trades, and it is possible to tell at the end of an agreed-upon time period (e.g., a planning week) if the assignment has been completed. Assignments are 'well defined' when those who are to execute the assignment understand what work is to be done, where and when it is to be done, and can determine what materials and information is needed in order to do the work. When possible, assignments should be so defined that it is possible at the conclusion of the plan period to tell by looking if they were performed.


demand leveling, heijunka, production leveling

→ see load leveling


Deming Cycle

→ see PDCA Named after W. Edwards Deming (1900-1993) and based on work of Walter A. Shewhart (1891-1967).


dependence, interdependence

Defining a relationship between two or more activities, concepts, or things.

  1. Sequential dependence: one preceding the other, e.g., predecessor-successor relationship between activities where the first must be completed before the second can start.
  2. Reciprocal dependence: Where two or more activities are related so that one cannot be started (or finished) without a certain measure of progress or completion having been achieved by the other.
  3. Shared resource dependence: Where two or more activities require the same resource during their execution, e.g., two activities sharing a crane.


A type of goal-directed, reductive (not deductive) reasoning. There are always many possible designs, especially if one is willing to relax constraints (requirements). Product design reasons from function to form. Process design reasons from ends to means.


design criteria

The characteristics required for acceptance of product or process design. Example: The structural engineer needs both geometric and load inputs from the architect, mechanical engineer, and electrical engineer. Loads need only be accurate within 20%.



Instruction or order issued by a Last Planner to direct workers (or production units) on what to do and possibly when or how to do it. Directives may apply to selection of prerequisites, resources, process execution, or criteria for output evaluation. → related to Activity Definition Model



earned value

An accounting method for project controls whereby partial credit is given to work completed, assessed based on an agreed-up schedule of values (earnings plan), with payments issued correspondingly.

This method is not lean: for example, it does not recognize the value of sequencing of work, creating specific handoffs, and shaping the work flow.

Reference: Kim, Y.-W. and Ballard, G. (2000). “Is the Earned-Value Method an Enemy of Workflow?” Proc. 8th Annual Conference of the International Group for Lean Construction (IGLC-8), Brighton, UK, 17-19 July.


Engineered To Order (ETO)

Product for which design and engineering are done in response to a specific request (order) from a customer, and that is then made to that design specification.

Illustration → see Assembled To Order
→ related to ATO, FTO, MTO, MTS, and CODP



→ see Engineered To Order


even flow production

Production with a steady throughput.


evenness of flow

Production achieved based on load leveling (heijunka).


Expected Cost (EC) [TVD]

In Target Value Design, an expression of the team's best estimate at the conclusion of the validation phase of TVD of what current best practice would produce as a price for the facility reflected in the accompanying basis of design documents. Typically, the Expected Cost will also be supported by benchmarking or other market data so it is calibrated in light of the market context.


(to) expedite

Effort to shorten the duration of an activity from what is typical or originally offered.

When initiated as a result of a delay or lack of confidence that the original duration will be met, expediting means ensuring the delivery of services or goods according to the agreed-upon terms and conditions, meeting requirements of timeliness, quality, quantity, packaging, etc. It is a waste because the supplier is not trusted to have made a reliable promise to their customer.


(to) explode [LPS]

To express a task in greater detail, typically by producing a flow diagram of the process of which the output is the task being exploded, then determining the sub-tasks needed to make the task ready for assignment and execution when scheduled. Sub-tasks are categorized in terms of the activity definition model, resulting in actions to clarify or specify directives and requests for prerequisites from suppliers, and reservation of needed resources.



Fabricated To Order (FTO)

Product put together from parts that are already designed, but as-of-yet have to be made, so as to meet the specifics of a
customer request (order).

Illustration →  see Assembled To Order

→ related to ETO, ATO, MTO, MTS, and CODP



Process of customizing materials by means of cutting, drilling, fastening, welding, etc.


factor [CBA]

In the context of Choosing by Advantages, it is an element, part, or component of a decision (Suhr 1999). Some thought or thing that is given consideration in the decisionmaking process.



Information about the gap between the actual level and the reference level of a system parameter (input, process, or output) that is used to alter the gap in some way. The distinction between positive- and negative feedback is based on the consequence and not the action. If the action triggered by feedback widens the gap between the reference and the actual level(s) of the system parameter, the feedback is called positive feedback; if it narrows the gap, it is called negative feedback. Unpredictability of the action-consequence relationship makes the study of feedback difficult.

Reference: Ramaprasad, A. (1983). “On the Definition of Feedback.” Behavioral Science, 28:4-13.



→ see first-in first-out


finished goods inventory

Inventory of goods (products or services) at the end of their production process, awaiting shipment or release to customers.

Illustration →  see inventory


first-in first-out (FIFO)

Inventory management discipline whereby the items that first entered a waiting position (queue) are the first to be withdrawn from there.


first-run study (FRS) [LPS]

First (or one of several) trial execution(s) of an operation as a test of capability to meet safety, quality, time and cost targets. The FRS begins several (e.g., 2 or 3) weeks ahead of the first run with a planning session in which the team that will do that work is involved in developing a detailed work plan at the step level of task breakdown, so each person on the team knows what they are to do. First run studies follow the plan-do-check-act cycle. The plan is developed, the first run is carried out, the results are checked against the targets. If the results are inadequate, the operation design is replanned and the test performed again. This continues until the operation is considered capable, then that way of doing that type of work is declared the standard to meet or beat. First-run studies are done ahead of the scheduled first start of the operation, while there is time to acquire different or additional prerequisites and resources. First run studies are one of three ways in which operations can be designed: the other two are virtual prototyping (virtual first run studies or VFRS) and physical prototyping (mock ups).


fishbone diagram, Ishikawa diagram

→ see cause-and-effect-diagram


Five Big Ideas & Emergent Outcomes

A set of organizing concepts that support Lean Project Delivery, developed to explain and organize the Sutter Health Lean Construction Initiative launched in the early 2000s.

The Five Big Ideas are:

  1. Collaborate, Really Collaborate (originally implied “specialty contractors involved at schematic design”),
  2. Optimize The Whole,
  3. Tightly Couple Learning with Action,
  4. Projects as Networks of Commitment, and
  5. Increase Relatedness.

The Emergent Outcomes are:

  1. Innovation,
  2. Competitive,
  3. Continuous Improvement,
  4. Reliability, and
  5. Build Trust.

G_Five Big Ideas

Figure source:


float [CPM]

Calculation of the difference between late start vs. early start of an activity, reflecting the amount of time by which an activity can be delayed without delaying the early finish time of the project.



→ see work flow

In general, refers to the F of Flow in the Transformation-Flow-Value (TFV) theory of production articulated by Koskela (1992, 2000).


(to) forecast

Prediction about the likelihood of occurrence of future events or performance.


forward pass calculation [CPM]

Calculation of the early start date and the early finish date of each activity in a network, taking into account the activity precedence relationships, by starting at the beginning of the schedule.


front end planning

The top level in the planning system hierarchy, above lookahead planning, dedicated to articulating high-level activities and their duration and sequencing as well as identifying milestones for an entire project, and resulting in a master schedule.



→ see Fabricated To Order


future state map [VSM]

A value stream map that describes a desired new (future) situation.



GANTT chart

Representation of a schedule, using a horizontal rectangle (bar) for each activity with the bar length scaled to match the activity duration, with activities placed one below the other and time on the horizontal axis.



The Japanese term referring to the location where value is added or the “work face,” e.g., the design office, fabrication shop, or on-site final assembly area. The lean practice of “going to the gemba” or “conducting a gemba walk “is for individuals to conduct first-hand observations (“go see for yourself”) rather than taking for granted abstractions of a situation seen and described by others.


genchi gembutsu

The Japanese term referring to “going to the gemba.”



(to) hand off

The act of releasing an output from a step or operation to the customer or production unit performing the next step or operation. Example: A structural steel design is “handed off” by the engineer to the steel detailer to complete shop drawings, a room that has been framed is “handed off” by the framer to the drywall installer, or all construction on a floor of a hospital is completed and it is “handed off” to the hospital personnel to begin “staff and stock” activities.


hand-off criteria

The criteria spelled out as conditions of satisfaction discussed and explicitly agreed upon between the provider and the customer (i.e., the parties to a hand-off).



The Japanese term meaning reflection, a means to learn from observation of a current situation, an experiment, a breakdown, etc.


heijunka, demand leveling, production leveling

→ see load leveling


House of Toyota

Representation of the fundamental building blocks that make up the Toyota Production System. G_House of Toyota - BW

Source: after visited 16 MAR 2015




→ see International Group for Lean Construction


importance of an advantage [CBA]

[unit of importance of advantage]

In Choosing by Advantages, importance refers to stakeholders’ assessment of the value of an advantage to meeting their requirements (e.g., the goals of a project) expressed by means of a criterion.



The combination of directives, prerequisites, and resources needed to execute a process.

→ see Activity Definition Model (ADM)



Assessing some feature of a process or completed work against a standard. That standard, rooted in someone’s purpose of need, is expressed in technical terms that can be observed and measured. Due to the risk that there is a break in value flow-down, even when you are in complete conformance with requirements, you may not contribute to value because your specifications are wrong.

Inspection may be done against purpose or against requirements.

→ see self-inspection and successive inspection


Instant CBA Method [CBA]

Application of the Choosing By Advantages method whereby a situation is very quickly assessed and the alternative with the greatest total importance of advantages is chosen.


Integrated Form of Agreement (IFOA)

A type of relational contract used in the delivery of capital projects developed by Lichtig (2006), that spells out commercial terms for project delivery, promotes the use of lean principles and methods, and is signed by multiple parties agreeing to collaborate on project delivery.

First tested on Sutter projects, the IFOA informed the development of Consensusdocs CD300 (

Reference: Lichtig, W.A. (2006). “The Integrated Agreement for Lean Project Delivery.” Construction Lawyer, American Bar Association, 26 (3), Summer.


Integrated Project Delivery™ (IPD)

A delivery system that seeks to align all project team members’ interests, objectives, and practices (even in a single business), through conceiving the Organization, Operating System and Commercial Terms governing the project. Team members would include the architect, key technical consultants as well as a general contractor and key subcontractors. It creates an organization able to apply the principles and practices of the Lean Project Delivery System (e.g., see

IPD is a registered business mark by Lean Construction Institute with the US PTO

IPD as used here is distinct from AIA’s use in AIA (2007). “Integrated Project Delivery: A Guide.” American Institute of Architects, available at

G_IPD color

Source: visited 19 NOV 2013



→ see dependence


International Group for Lean Construction (IGLC)

“The International Group for Lean Construction (IGLC), founded in 1993, makes up a network of professionals and researchers in architecture, engineering, and construction (AEC) who feel that the practice, education, and research of AEC have to be radically renewed in order to respond to the challenges ahead.

Our goal is to better meet customer demands and dramatically improve the AEC process as well as product. To achieve this, we are developing new principles and methods for product development and production management specifically tailored to the AEC industry, but akin to those defining lean production that proved to be so successful in manufacturing.

The distinguishing trait of this Group is its emphasis on theory. We view that the lack of an explicit theory of construction has been a major bottleneck for the progress in the AEC field. Conversely, we assume that the clarification of the theoretical foundation of construction, along with principles and methods emanating from the new foundation, would be the most effective means for the renewal of the AEC industry.”

The main activity of the IGLC is to organize annual conferences so as to bring the community together, promote sharing, and advance learning. You can find papers from past conferences, information on the upcoming conference, and more information at

Reference: visited 1 MAR 2015



Stock on hand (e.g., materials or information), often divided between:

  1. Raw materials inventory
  2. Work-in-process (WIP) inventory, and
  3. Finished goods inventory

One of 7 wastes defined by Ohno (1988) referring to products or materials awaiting further processing before being ready for release as a finished good to a customer.


Image source: Iris D. Tommelein 2015


Ishikawa Diagram, fishbone diagram

→ see cause-and-effect diagram



Repetition of a process that already has been performed once.

  1. Negative iteration refers to rework without value being added.
  2. Positive iteration refers to, e.g., learning taking place.




The Japanese term referring to the quality control process with four steps:

  1. Detect the abnormality.
  2. Stop.
  3. Fix or correct the immediate condition.
  4. Investigate the root cause and install a countermeasure.

Jidoka is one of two pillars in the House of Toyota, the other pillar being Just in Time (JIT). Reference: Rosenthal, M. (2011). The Essence of Jidoka. Society of Manufacturing Engineers (SME), online at


job shop

Production system that accommodates making one-of-a-kind products whereby processing stations (machines) are laid out by functional grouping so that each unit being produced is likely to have to follow a jumbled flow from one to the next, according to the processing steps it requires. → see batch flow for an illustration


Just in Time (JIT)

Delivery of input to a customer just prior to when the customer needs it. Just in Time is one of two pillars in the House of Toyota, the other pillar being jidoka. JIT gets used to refer to the TPS itself.



The Japanese word referring to making fundamental, radical changes in order to improve a production system or business. → in contrast to kaizen.


The Japanese word referring to an opportunity for continuous improvement achieved by making incremental changes. → in contrast to kaikaku.


The Japanese word referring to a card (sign or signal) that indicates how many and what units are to be made by a production unit (production kanban) or taken from inventory as input for a production unit (withdrawal kanban) (Figure 1). G_kanban-1 Figure 2 illustrates that in construction, the ready-mix trucks used for batching and delivering concrete can act as kanban. Each time an empty one arrives at the batch plant (the supplying process), it must be (re)filled with the pre-agreed upon mix and up to the desired quantity. The truck then returns to the site (the customer process) where the concrete will be placed. This batch process does not allow any inventory of product to be maintained (no supermarket) because the product is perishable. G_kanban-2 Kanban is a means to limit the amount of inventory in a production system. It is a means to match and keep together the information flow with the material flow in a production system (Johnson and Broms 2000 p. 92). Example: A milk-run system uses empty bottles for kanban (containers). References: Rother, M. and Shook, J. (1998). Learning to See: Value Stream Mapping to Create Value and Eliminate Muda. v.1.1, Oct., The Lean Enterprise Institute, Brookline, Mass. Figures 1 and 2 are from Tommelein, I.D. and Li, A.E.Y. (1999) “Just-in-Time Concrete Delivery: Mapping Alternatives for Vertical Supply Chain Integration.” in Tommelein, I.D. (editor), Proc. 7th Annual Conference of the International Group for Lean Construction (IGLC-7), 26-28 July, held in Berkeley, CA, USA, pp. 97-108.


A structured routine you practice deliberately as a beginner, so its pattern becomes a new habit. References: Rother, M. (2009). Toyota Kata: Managing People for Improvement, Adaptiveness and Superior Results. McGraw-Hill, 306 pp. Rother’s website:

Kingman's Formula aka. VUT equation

A mathematical expression of the relationship between waiting time vs. utilization, variability and cycle time.

Tq ≈ V * U * T


Tq is the expected time spent waiting in a queue

V is a characterization of the variability in the system

U is a characterization of the utilization of the system, that is, how close to 100% capacity it is running

T (or CT) is the cycle time, that is, the process time and wait times in-between process steps

References: Kingman, J. (1961). “The single server queue in heavy traffic.” Mathematical Proceedings of the Cambridge Philosophical Society, 57 (4): 902. Wikipedia:

(to) kit

Grouping of various parts and instructions (e.g., by putting them in a bag or bundle), to be delivered as one unit to the work face, also known as “bagging and tagging.”



Language Action Perspective (LAP)

→ see reliable promise


last-in first-out (LIFO)

Inventory management discipline whereby the items that last entered a waiting position (queue) are the first to be withdrawn from there.

→ in contrast with first-in first-out (FIFO)


Last Planner™

The person making commitments on behalf of and assignments to direct workers.

Example: ‘Squad boss’ and ‘discipline lead’ are common names for last planners in design processes. ‘Superintendent’ (if a job is small) or ‘foreman’ are common names for last planners in construction processes.


Last Planner™ System (LPS)

The collaborative, commitment-based planning system that integrates should-can-will-did planning. It includes master scheduling and phase planning to define what SHOULD be done, lookahead planning based on constraints identification and removal (the make-ready process) to establish what CAN be done, weekly work planning based on reliable promises reflecting what WILL be done, and learning based upon analysis of PPC (comparing DID against WILL) and reasons for variance.

G_Last Planner System

Image source: Glenn Ballard

Ballard, G. (1994). The Last Planner. Northern California Construction Institute, Monterey, California.
Ballard, G. (2000). The Last Planner System of Production Control. PhD Dissertation, Univ. of Birmingham, UK,
Ballard, G. and Tommelein, I.D. (2016). “Current Process Benchmark for the Last Planner System.” Project Production Systems Laboratory, University of California, Berkeley, CA,
Ballard, G. and Tommelein, I.D. (2021). 2020 Benchmark of the Last Planner System. Project Production Systems Laboratory, University of California, Berkeley, CA, available at [reprinted in the Lean Construction Journal]


Last Responsible Moment (LRM)

While considering alternatives, the last responsible moment for one alternative is the time at which, if that alternative is not selected and pursued, that alternative is no longer viable.

→ used in Set Based Design (SBD)

Reference: term coined in Lane, R. and Woodman, G. (2000). “Wicked Problems, Righteous Solutions – Back to the Future on Large Complex Projects.” Proceedings 8th Annual Meeting of the International Group for Lean Construction, August 17-19, Brighton, UK.


→ see Lean Construction Institute


lead time (LT), supplier lead time  ∆

[unit of time]

The time it takes a product to go from being ordered to being delivered as input to a production process.

Example: The transformer has a 20 week lead time: it takes 20 weeks to be designed, manufactured, and delivered to our site.



Creating more value for customers with fewer resources.

Reference: Lean Enterprise Institute (2016-04-14)


Lean Construction, Lean Project Delivery

Application of lean thinking to the designing and making (or delivery at large) of capital projects (or projects in general).

→ related Lean Project Delivery System (LPDS)
→ see International Group for Lean Construction (IGLC)


Lean Construction Institute (LCI)

The Lean Construction Institute (LCI) is a non-profit organization, founded in 1997 by Greg Howell and Glenn Ballard to promote lean thinking in the architecture, engineering, and construction industry.



Lean Project Delivery System (LPDS)

Representation of the delivery of a project from determining that which helps clients better achieve their business purposes through final use. Positive iteration is encouraged within each phase so as to prevent negative iteration between the phases. Production control, work structuring, and learning are continuing functions.


Image source: Glenn Ballard


Lean Triangle

Triangle depicting the three domains within which project delivery systems operate:

  1. The project organization,
  2. The project’s “operating system,” and
  3. The commercial terms binding the project participants.

Integrated Project Delivery seeks to systematically attack the deficiencies of “traditional” project management practices observed in each of these domains.

G_Lean Triangle

Reference: Thomsen, C., Darrington, J., Dunne, D., and Lichtig, W. (no date). Managing Integrated Project Delivery. CMAA, McLean, VA, 104 pp.



The process of gaining new knowledge or insights whose implementation may improve product and process development.

Learning can stem from experimentation (using PDCA) or breakdowns.


least preferred alternative [CBA]

→ see advantage



→ see last-in first-out


line-of-balance diagram, location-based management system (LBMS), location-based schedule, repetitive scheduling method, velocity chart

Two-dimensional representation of a schedule broken down by units of work (e.g., repetitive spatial units such as floors, rooms, or road sections in-between stations) using a line for each activity, so as to depict the continuous application of resource(s). The horizontal axis may represent time and the vertical axis the unit of work (or space), or the axes may be flipped.

Reference: Harris, R.G. and Ioannou, P.G. (1998). “Scheduling projects with repeating activities.” Journal of Construction Engineering and Management, ASCE, 124 (4) 269-278.


Little’s Law ∆



WIP is Work-in-Process [unit of work]
TH is Throughput [unit of work/unit of time]
CT is Cycle Time [unit of time]

Example: A builder uses even-flow production: they start (and finish) about 3.2 houses each month. It takes them about 14 weeks (the cycle time) to complete each house. Using Little's Law you can thus compute that have about 11 houses under construction at any one time.

Given: TH = 3.2 houses/month
CT = 14 weeks * (1 month)/(4 weeks) = 3.5 months
Compute: WIP = 3.2 houses/month * 3.5 months = 11 houses

Wardell, C. (2003). “Build by numbers.” Builder Magazine, January 1, pp. 1-6.
Also see Hopp, W.J. and Spearman, M.L. (2000). Factory Physics. 2nd ed., McGraw-Hill, New York, NY, 698 pp.



The amount of output expected from a production unit or individual worker within a given time. Within a weekly work plan, what is to be accomplished by a design squad or individual designer, engineer, draftsperson, construction craft worker, crew, etc.

A quality assignment “loads” a resource within its capacity.


load leveling, demand leveling, heijunka, production leveling

An approach to smooth production flow when a mix of products is to be produced, by identifying for a selected time period, the smallest batch size at which to produce each specific product in the mix, before switching over to make another product in the mix.

The goal is to increase the regularity by which products of different types are produced, countering the tendency to batch in reaction to frequent change-over times, even though customer demand may be irregular. This practice creates the need to focus on reducing setup and changeover times. The resulting flexibility enables the production system to cope with varying demand and market fluctuations without incurring additional production cost for such customization.

Note that in project production, demand can be leveled by means of work structuring (including planning). We shape—if not create—our own demand.

Example: customer demand for AAAABBAAAACC gets leveled to ABAACAABAACA.

→ related to SMED


location-based management, location-based management system (LBMS)

Scheduling repetitive units of work based on the line-of-balance method. This includes representing the schedule with time on one axis and units of space (locations) on the other axis, and the use of time buffers to accommodate variation.

Reference: Kenley, R. and Seppanen, O. (2010). Location Based Management for Construction: Planning, Scheduling, and Control. Spon Press.


long lead materials

Materials that take a long time to specify and acquire, so that typically they cannot be pulled to site within the lookahead window.

In the extreme, some materials must be procured even before the project starts; without them, there is no project.

Example: The CII report on PEpC (Procure, Engineer, procure, Construct) distinguishes the big-ticket items that must be Procured (uppercase P) up-front (e.g., a turbine-generator for a power plant), from smaller items that can be procured after engineering (lowercase p).




→ see make ready


lookahead planning, lookahead scheduling

→ see make-ready planning


lookahead window

How far ahead of scheduled start activities in the master- or phase plan are subjected to explosion, screening, or make ready. For example, lookahead windows may extend from 3 to 12 weeks into the future.

The duration of the lookahead window is defined in function of the ability to pull material to site (to obtain what is needed when it is needed, aka. to make ready). This duration depends on your ability to predict in advance at the task level what work needs to be done in the future. When there is a lot of uncertainty in the system, you may not be able to break down work to the task level.



→ see Last Responsible Moment



Made To Order (MTO)

A product that has been designed, but is made (physically realized) only at the time when a specific customer demands it. One category in a classification that distinguishes how long a product or service remains generic vs. becomes customer specific in its production.

Illustration see Assembled To Order (ATO)

→ related to ATO, CODP, ETO, FTO, and MTS


Made To Stock (MTS)

A product that is made based on a forecast of customer demand, and then stored in inventory (finished goods) until a specific customer wants it.

Illustration see Assembled To Order (ATO)

→ related to ATO, CODP, ETO, FTO, and MTO


(to) make ready

To take actions needed to remove constraints from tasks (assignments) in order to make them sound.


make-ready plan [LPS]

The output of make-ready planning, resulting from exploding master- or phase-schedule activities by means of the activity definition model, screening the resultant tasks before allowing entry into the make-ready window or advancement within the window, and taking actions needed to make tasks ready for assignment when scheduled. It is dedicated to controlling the flow of work through the production system. Make-ready plans may be presented in list form or bar charts.

NOTE: a make-ready plan is a kind of lookahead schedule, specifically one developed using the principled approach of the Last Planner System. We avoid using lookahead as it is a term used in practice also on non-lean projects.


make-ready planning [LPS]

The process of taking activities from the master- or phase schedule to the make-ready plan (lookahead plan), and then exploding, screening, or making them ready in a lookahead window.


make-ready (time) window [LPS]

How far ahead of scheduled start activities in the master- or phase schedule are subjected to explosion, screening, or making ready. Typically make-ready (time) windows extend from 3 to 12 weeks into the future. It is assumed that the duration of this window is defined in function of the ability to pull material to site. This duration depends on your ability to predict in advance at the task level what work needs to be done in the future. The greater the uncertainty in the system, the later tasks can be broken down into operations.


Management by Means (MBM)

A mindset and approach for managing an organization or company that relies on nurturing people, organizing work systematically, and continuously improving on standard processes.
Characterization of the living systems approach adopted in the Toyota Production System and in Scania’s modular design of trucks.

→ in contrast with management by results

Reference: Johnson, H.T. and Bröms, A. (2001). Profit Beyond Measure: Extraordinary Results through Attention to Work and People. Simon and Schuster, 272 pages.


Management by Results (MBR)

A mindset and approach for managing an organization or company that relies on hitting financial targets and other output metrics.

The contrast between driving work with financial targets (MBR), and organizing work systemically (MBM) was clearly enunciated by Edward Deming several years ago: “If you have a stable system, then there is no use to specify a goal. You will get whatever the system will deliver. A goal beyond the capability of the system will not be reached. If you do not have a stable system, then there is no point in setting a goal. There is no way to know what the system will produce.”

→ in contrast with management by means

Reference: Johnson, H.T. and Bröms, A. (2001). Profit Beyond Measure: Extraordinary Results through Attention to Work and People. Simon and Schuster, 272 pages.


Market Cost (MC) [TVD]

In Target Value Design, what an owner may expect to pay for a desired asset based on comparison to historical market cost for similar assets. Hence, it is the initial expected cost determined through benchmarking to market of the owner's wants. The comparison to allowable cost determines whether or not to proceed with validation. It comes into play in business planning or in the course of the budget validation.


mass customization

The process of making a generic product customer specific. This may be done by fabricating components and stocking them, so they will be readily available when the customer specifications become known.

→ see Assembled To Order


master plan, master schedule

Plan or schedule covering an entire project start-to-finish, then further detailed and validated in phase planning, the activities in which are then exploded when creating the make-ready plan.


master planning, master scheduling

Development of a master plan (schedule), typically with the involvement of only high-level project participants (e.g., the general contractor) and done well in advance of the start of a project. In traditional practice, the exploration required to decide if to accept the challenge of meeting a target completion date is confused with determining a master schedule, which-in the lean philosophy-should be kept at milestones, to be progressively detailed phase by phase, collaboratively using phase planning (or pull planning) with those who are to do the work in each phase.


matching problem

Challenge encountered when combining unique products with other unique products, e.g., combining {a, b, c, …} and {1, 2, 3, …} in that order to form {a1, b2, c3, …}.


Image source: Iris D. Tommelein



→ see Management by Means



→ see Management by Results


merge bias

Phenomenon that occurs when two or more parallel paths of activities must be completed in order for the successor activity to start. Given that each path has its probability of governing the start time of that successor, all path probabilities must be combined in order to describe the likelihood of the successor starting.

Ignoring merge bias results in schedules being too optimistic (short) in their duration.

G_merge bias

Image source: Iris D. Tommelein



A point in time on the master plan (master schedule) that defines the end or beginning of a phase or a contractually required event.


mistakeproofing, poka yoke

The practice of designing products or processes to eliminate (or at least to reduce) the probability or impact of mistakes and defects in use or execution.

Reference: Shingo, Shigeo (1986). Zero Quality Control: Source Inspection and the Poka-Yoke System. Taylor & Francis.



The Japanese word for a three-part problem prevention process developed at Toyota called GD3 or “Good Design, Good Discussion and Good Dissection.”

McLeish, James and Haughey, William (no date). “Introduction to Japanese Style Mizenboushi Methods for Preventing Problems Before They Occur.” visited 9 March 2015.
Yoshimura, Tatsuhiko (2002) Toyota Style Mizenboushi Method – GD3 Preventive Measures – How to Prevent a Problem Before it Occurs. In Japanese, Tokyo, JUSE Press.



The design practice that involved identifying groupings of parts to be configured in different ways thanks to clearly defined interfaces.

Reference: Baldwin, C.Y. and Clark, K.B. (2000). Design Rules, Volume 1: The Power of Modularity. MIT Press, 483 pp.



One of 7 wastes defined by Ohno (1988) referring to unnecessary movement by people.



→ see Made To Order



→ see Made To Stock



The Japanese word for waste referring to anything that fails to add value to the product or service delivered to the customer, i.e., anything unnecessary.

Muda is broken down into Ohno’s (1988) 7 Wastes.

Related → see muri and mura


multi-functional diagram, swimlane diagram

→ see cross-functional diagram


(to) multiskill

Process whereby production units—individuals or groups specialized in one skill or technique—acquire skills and techniques typically used by other production units.

→ also see (to) specialize



The Japanese word for waste stemming from unevenness or inconsistency of workload imposed on people or machines (resources). It may be alleviated through application of heijunka and kanban systems.

Related → see muri and muda



The Japanese word for waste stemming from overburdening people or machines (resources). It may be alleviated, for example, through application of 5S.

Related → see mura and muda



negative iteration

Repetition that is considered to be non-value adding to the process but that is necessary in order to reach a solution.

→ in contrast to positive iteration

Reference: Ballard, G. (2000). “Positive vs negative iteration in design.” Proceedings 8th Annual Conference of the International Group for Lean Construction, IGLC-6, Brighton, UK, 8 pp.



The principle of making decisions slowly by consensus, thoroughly considering all options, and then implementing decisions rapidly (Principle 13 of Toyota’s 14 Principles). This may be achieved for example by using A3 thinking, Set Based Design, and Choosing by Advantages.


network of commitments

The web of reliable promises necessary to deliver any project. The role of management is to articulate and activate the unique network of commitments required to deliver each project.


non-value-adding time (NVAT) [VSM]

Time that workers or production units spend on a process step that is not of value to the customer (i.e., that the customer is not happy to pay for).



→see non-value-adding time



Oba, Obeeya

→ see Big Room


Ohno circle

Used when standing over an extended period of time in one location (in a hula hoop or in a circle drawn on the ground) in order to observe first-hand what is taking place in a surrounding area (work place). Named after Taiichi Ohno (1912-1990).



Part of a process that can be designed and tested in a first run study in order to figure out what specific steps to take.



The product or service resulting from execution of a (transformation) process.


output rate, throughput

[unit of product/unit of time] The average time between outputs of successive units. Example: A builder completes houses at an output rate of 3.2 houses/month. Related → see Little's Law



One of 7 wastes defined by Ohno (1988) referring to taking more processing steps or more time, or producing work that exceeds the customer’s explicit expectations.



One of 7 wastes defined by Ohno (1988) referring to producing more than needed before it is needed.




→ see Project Production Systems Laboratory


paramount advantage [CBA]

[unit of importance of advantage]

In Choosing by Advantages, the paramount advantage is the beneficial difference that is considered to be of greatest value to the stakeholders making the decision. This advantage therefore sets the scale of Importance of Advantages (e.g., it may be given the value 100 on the scale where 0 is defined by all least-preferred attributes).


PLAN DO CHECK ACT (PDCA), PLAN DO STUDY ACT (PDSA), Deming Cycle, Shewhart Cycle

G_plan-do-check-actThe cycle of scientific experimentation, used for example in pursuit of continuous improvement.

Example: PDCA cycle for a learning experiment using a first run study of a construction operation includes a detailed plan for an operation developed prior to starting work, structured to achieve safety, quality, time and cost objectives. The plan is developed with those involved in doing the work, tested and improved. The plan includes timing and location of activities, work flow, balanced work load, tools, release of work downstream, etc. The actual process is recorded and analyzed to identify improvements.

  • ‘Plan’ an experiment.
  • ‘Do’ the experiment.
  • ‘Check’ to see if your expected results were achieved. Once satisfied,
  • ‘Act’ on the findings; e.g., declare a new standard process, incorporate into education and training, execute an implementation plan, etc.

G_PDCA example



G_prevent-detect-correct-analyzeReinterpretation of the PDCA cycle that fosters learning from experimentation, to fostering learning from breakdowns (Ballard 2014). An effective process for managing breakdowns does what can be done to Prevent breakdowns, Detects the occurrence of breakdowns that happen despite our best efforts–as close to the point of origin as possible; cleans up the mess, making sure to find and Correct any ripple effects; Analyzes why the breakdown occurred; and takes action to Prevent re-occurrence.

  • Prevent: Preventive action depends on our understanding of causation; what causes various types of breakdowns. When breakdowns occur despite our efforts to prevent, we have something more to learn about cause and effect.
  • Detect: Some errors (deviations from standard) are virtually impossible to prevent completely, but can be ‘captured’ before causing breakdowns. When breakdowns do occur, we want to detect them as close to their point of origin as possible, to contain the damage. This may be done by:
    • Using small batches
    • Doing self-inspection
    • Doing successive inspection
    • Mistakeproofing detection where possible
    • Promoting ‘family feeling’ among team members to encourage speaking up
    • ‘Capturing’ errors before they become defects
  • Correct: When breakdowns are detected, the first step is to take corrective action. For example, if we have an error in a drawing, we correct the error and replace the drawing.
  • Analyze: Corrective action is not enough if we want to prevent re-occurrence. We must analyze the breakdown to understand why it happened in order to understand causality. That’s the only way we can prevent re-occurrence.

Ballard, Glenn and Tommelein, Iris (2015). “Built in Quality Cycle.” Project Production Systems Laboratory, P2SL White Paper No. 1, December 25.


PDCA Composite

G_PDCA compositeThe two PDCA cycles, one for learning from experiments and one for learning from breakdowns, work together. The Analyze step in learning from breakdowns corresponds to the Plan step in learning from experiments. We first try to understand why what happened happened, then design an experiment to test our explanation, our attempt to understand causality. Once the experiment is carried out and the findings examined, we act to prevent re-occurrence of the breakdown.


Percent Plan Complete (PPC) [LPS]

Metric used in the Last Planner System to gauge plan reliability. The number of planned completions divided into the number of actual completions in a given time period, usually referring to tasks in a commitment plan (e.g., a weekly work plan, a daily work plan, or hourly work plan).

PPC is based on the binary assessment whether or not a task is 100% complete (“done done”).

NOTE: PPC is not an earned value metric. Earned value metrics give partial credit to work underway (e.g., 20% done).



The individual or production unit engaged in a conversation for action who agrees to do work and deliver a product or service either requested by or offered to a customer.



Program Evaluation and Review Technique. Planning technique developed in the late 1950s to determine the duration of projects with highly uncertain activity durations.

NOTE: PERT computations are too optimistic as they ignore constraints imposed by resource loading (including shared resources) and the merge bias effect.



Part of a project, the hinge point in regards to specifying what needs to be done vs how to do it.

A time period of a project during which a specific group of activities is scheduled to be accomplished (e.g., building design, completion of foundations, erection of exterior walls, building dry-in), leading to the accomplishment of a defined milestone.


phase planning, Reverse Phase Scheduling (RPS) [LPS]

One level in the Last Planner System, where a phase gets broken out from the master plan, and people responsible for the work in that phase jointly develop the plan. People in a “design phase” may include engineers, architects, owners, designers; perhaps also permitting agencies. People in a “construction phase” may include designers, the general contractor and specialty contractors, perhaps also inspectors and commissioning agents.

The team starts at the end of the phase (the customer) and pulls (works backward) to determine (1) what chunk(s) of work will deliver the hand off(s) needed by this customer (identifying the requirements to declare a chunk of work complete) and (2) the inputs, directives, and resources needed to perform the chunk(s).

The latter in turn become the customers and the pulling gets repeated until the entire phase is broken down in a network of work chunks. Work chunks specified by their outputs (I give) and needs (I get) may be written down on sticky notes (color-coded by performer) and pasted on a wall.

The chunks are then rearranged based on the start and end time of the phase, the durations negotiated to complete each chunk of work, allocation of slack where needed, and work structuring to achieve work flow.


plan reliability [LPS]

The extent to which a plan is an accurate forecast of future events, measured by Percent Planned Complete (PPC).

Example: If your weekly work plans have a 60% PPC, they accurately predict completion/release of 60% of the weekly assignments.



Defining criteria for success and producing strategies and directives for achieving success.

The collective act of discussing and developing a strategy for future performance. Lean planners understand that all plans are forecasts and all forecasts are wrong, that the further in advance the plan is developed, the more wrong it will be; and that the greater the detail of the plan, the more wrong it will be.

Planning can also be thought of as “practicing” or “rehearsing” for future performance.


Plus / Delta

A discussion at the end of an activity, meeting, or project used to evaluate and learn from its performance by capturing:

  • Plusses: What worked or produced value during the session? and
  • Deltas: What could we do differently or better next time to improve the process or outcome?

Point Based Design (PBD)

A design methodology whereby one specialist explores (one or a few alternative) solutions to their part of the problem, selects one, and that passes that one to the next design specialist.

→ in contrast to Set Based Design


point speed

[unit of time/unit of production]

How fast an individual assignment is completed.


poka yoke

→ see mistakeproofing


positive iteration

Repeating of a task that was done previously, e.g., in order to explore further alternatives and to foster learning.

→ in contrast to negative iteration

Reference: Ballard, G. (2000). “Positive vs negative iteration in design.” Proceedings 8th Annual Conference of the International Group for Lean Construction, IGLC-6, Brighton, UK, 8 pp.



→ see Percent Plan Complete



Consistency of results when measured repeatedly.

As distinct from accuracy.

→ related to predictability

Example: The survey crew had precisely staked out the footing’s location, but that was useless as they had started to measure from the wrong reference point.



That which comes earlier (precedes) in time

→ inverse of successor



The degree to which something can be forecast within a certain time frame and with a degree of accuracy and precision.


Image source:


prerequisite work

Work done by others on materials or information that serves as an input or substrate for your work.

Example 1: You need to know the surface area of glass, provided by the architect, in order to size cooling equipment.

Example 2: The framing must be in place before drywalling can start.


Principles of Choosing By Advantages [CBA]

Principle 1: Decisionmakers must learn and skillfully use sound methods. (The pivotal cornerstone principle)
Principle 2: Decisions must be based on importance of advantages. (The fundamental rule)
Principle 3: Decisions must be based on anchored to the relevant facts. (The principle of anchoring)
Principle 4: Different types of decisions call for different types of methods. (The methods principle)
Principle 5: Simplify simple decisions by taking fewer steps, e.g., use instant CBA.
Principle 6: Simplify complex decisions by taking smaller steps, e.g., use the tabular method to break the decision into parts.
Principle 7: Simplify all decisions by correctly using correct data.
Principle 8: Money decisions call for special methods. E.g., chart total importance vs. cost.
Principle 9: Different money-decisionmaking contexts call for different money-decisionmaking methods.

Reference: Suhr – workbook


Principles of the Toyota Way, 14 Principles of the Toyota Way

Section I: Long-Term Philosophy

  1. Base management decisions on long-term philosophy even at the expense of short-term financial goals

Section II: The Right Process Will Produce the Right Results

  1. Create continuous process flow to bring problems to the surface
  2. Use “pull” systems to avoid overproduction
  3. Level out the workload (heijunka) (work like the tortoise, not the hare)
  4. Build a culture of stopping to fix problems to get quality right the first time
  5. Standardized tasks and processes are the foundation for continuous improvement and employee empowerment
  6. Use visual control so no problems are hidden
  7. Use only reliable, thoroughly tested technology that serves your people and processes

Section III: Add Value to the Organization by Developing Your People

  1. Grow leaders who thoroughly understand the work, live the philosophy, and teach it to others
  2. Develop exceptional people and teams who follow your company’s philosophy
  3. Respect your extended network of partners and suppliers by challenging them and helping them improve

Section IV: Continuously Solving Root Problems Drives Organizational Learning

  1. Go and see for yourself to thoroughly understand the situation (genchi genbutsu)
  2. Make decisions slowly by consensus, thoroughly considering all options; implement decisions rapidly (nemawashi)
  3. Become a learning organization through relentless reflection (hansei) and continuous improvement (kaizen)

Reference: Liker, J. and Meier, D. (2006). The Toyota Way Fieldbook.



Sequence of operations, each one comprising a sequence of steps.


process capability

Probability distribution describing the variation in the geometry of the material output of a process under normal operating conditions. This definition pertaining to geometry equally applies to any material, resource, or process property such as duration, temperature, impact strength, etc.


process map

A flowchart identifying the operations in the process, steps in each operation, and work time for each step.


production batch

→ see batch


production control [LPS]

Proactively managing the make-ready process so that tasks will meet the Last Planner’s quality criteria. This includes actively making work ready, executing work, and then tracking progress against plan, taking corrective action, and adjusting the plan.


production leveling, demand leveling, heijunka

→ see load leveling


production system

A sequence of interdependent steps that results in the delivery of a product or service.


production system design

Determining the characteristics of a system for designing and making products, either goods and/or services.


production unit

A group of direct production workers that do or share responsibility for similar work, drawing on the same skills and techniques.
Example: a team of electrical designers and engineers responsible for a specific area or functions of a building.



The ratio of the output produced to the resources used in its production.

Example: 3 drawings per labor hour.



High level description of what work must be done or service delivered in order to fulfill a defined purpose. A project can be described using a master schedule and consists of phases.


Project Production Systems Laboratory (P2SL)

Research laboratory at the University of California, Berkeley, founded in 2005 by Iris Tommelein and Glenn Ballard to conduct research in order to develop the theory and practice of lean thinking applied to project-based production, including lean thinking in the architecture, engineering, and construction industry (lean construction).




The commitment by a speaker (performer) to a listener (customer) to take some action to produce a mutually understood result (Conditions of Satisfaction) by a definite time in the future.

→ see reliable promise


(to) pull

Initiating the delivery of input(s) based on the readiness of the process into which they will enter (the customer process) for transformation into output(s).

Example: Request delivery of prerequisite information at or before the time you will be ready to process that information.

NOTE: what is different here is that the readiness of the process is known rather than forecast or wished. Either the process is ready prior to requesting delivery or plan reliability is sufficiently high that work plans can be used to predict readiness.


pull planning, pull scheduling

→ see phase planning


(to) push

Releasing materials, information, or directives possibly according to a plan but irrespectively of whether or not the downstream process (the customer process) is ready to process them.


push vs. pull

A push system schedules the release of work based on demand, while a pull system authorizes the release of work based on system status.

Reference: Hopp and Spearman, S. (1996). Factory Physics. p. 317




Meeting requirements.

Lichtig (2011) defines it as “Consistently producing a product (outcome) that meets customers’ expectations and that is fit for the purpose intended.”

Related → see Built-in Quality


quality assignment

Assignment that meets all quality criteria for release to the customer process.


quality assurance/quality control (QA/QC)

Related → see Built-in Quality


quality criteria (plural of quality criterion) [LPS]

In the Last Planner System, these specify what makes for a quality assignment:

  1. definition,
  2. soundness,
  3. sequence,
  4. size, and
  5. learning.



raw materials inventory

Materials obtained from suppliers; as-of-yet unused input to be transformed in a production process and output as finished goods. Illustration → see inventory


realities or truths of planning (not quite Principles)

  • Plans are forecasts and forecasts are always wrong.
  • The further out into the future you plan, the more wrong you are.
  • The greater detail you plan, the more wrong you are.


…for failing to complete weekly assignments; e.g., lack of prerequisites, insufficient time, unclear directives. Reasons can also be sought for failing to advance scheduled tasks from master schedule to make-ready schedule or from one week to the next within the make-ready schedule.


reciprocal dependence

Mutual dependence. → see dependence Example: The architect was waiting for input from the structural engineer, but the structural engineer also was waiting for input from the architect.


reconsideration phase [CBA]

The process of gaining new knowledge or insights based on having completed a CBA table and chart showing money vs. importance of advantages, leading to modifying the CBA table and chart, and possibly resulting in making a different choice.


reliable, reliability

To achieve what was promised as promised.


reliable promise, reliable promising

Promise reached by sticking to the steps of the Language-Action Perspective (LAP) cycle:

  • Making a request,
  • Committing,
  • Declaring Complete, and
  • Declaring Satisfaction, while striving to meet the Conditions of Satisfaction (e.g., meeting a Completion Date).

References: Flores, F. (1982). Management and Communication in the Office of the Future. PhD Dissertation, University of California, Berkeley, CA. Winograd, T. and Flores, F. (1987). Understanding Computers and Cognition: A New Foundation for Design. Reading, MA: Addison-Wesley, 224 pp.



Specification of what must be satisfied in order for an alternative to be acceptable. In Choosing by Advantages, a must criterion.



Labor or instrument of labor, including tools, equipment, and space. Resources have production capacities as well as costs. Consequently, materials and information are not resources, but rather what resources act on or process. NOTE: in CBA, Suhr (1999) defines money as a resource.


Reverse Phase Planning, Reverse Phase Scheduling (RPS)

→ see phase planning



One type of iteration, where work that was done before (which may have been thought to have been completed) is being redone.



Reverse Phase Scheduling → see phase planning


safe, safety

Not harmful.


→ see Set Based Design


→ see Supply Chain Management


A type of waste of materials (partially worked on or completed) that does not meet the applicable quality criteria and is therefore rejected.

(to) screen [LPS]

In the Last Planner System, determining the status of tasks in the lookahead window (make-ready planning window) relative to their constraints, and choosing to advance or retard tasks based on their constraint status, considering the likelihood and timing of those constraints being removed. Retarding tasks that we know cannot be made ready in the time remaining to their planned start time. G_Last Planner System

Image source: Glenn Ballard

Example: The master schedule indicates that the installation of the air handling units (AHUs) must start 6 weeks from now, so we want to move the activity “install AHUs” into our 6-week lookahead plan. However, when screening that activity, we realize that it will be at least another 3 weeks before the design will be finalized, the design will then need approval, and fabrication of the units takes 4 weeks. So, facing this new reality, rather than move this activity into the lookahead while knowing we cannot make it ready in time, we better retard it, and replan accordingly. Related → see (to) screen and (to) shield


Process whereby the performer of a task confirms that the handoff produced conforms to requirements and all known purposes including the purpose expressed in the Conditions of Satisfaction (COS) of the immediate and ultimate customers. This eliminates the defects against known requirement and it eliminates the defects that are relevant to the next trades (but may not see what is important to people further downstream). Related → see source inspection

sequence [LPS]

Quality criterion for selecting assignments among those that are sound in priority order and in constructability order.

sequential dependence

Relationship between two activities or tasks when one must be done before the second can start. Such dependence often presumes sequential finality but that is often false.

sequential finality

A predecessor activity or task being 100% complete (“final” or “done-done”) when a successor starts.

Set Based Design (SBD)

A design methodology whereby sets of alternative solutions to parts of the problem are maintained until their last responsible moment(s), in order to find by means of set intersection the best combination that solves the problem as a whole. → in contrast to Point Based Design

setup time, setup cost

Time needed and cost incurred when getting ready for a run of a different production item, as needed to clean and adjust equipment, remobilize, obtain materials, etc. Related → see Single Minute Exchange of a Die

(to) shield [LPS]

In the Last Planner System, not releasing work to production units because it does not meet quality criteria; the work is not a quality assignment. Shielding is akin to “stopping the assembly line” in manufacturing. The purpose of shielding is the make production units less subject to uncertainty and variation, thereby providing them with greater opportunity to be reliable. Not allowing assignments that are known to be defective to move down to the next planning level. Related → see (to) screen

Short Interval Planning System (SIPS)

A planning approach that breaks down the work space into relatively small units, where production units each in turn are given a short amount of time in order to complete their work.

should-can-will-did [LPS]

Distinction made in the Last Planner System. To be effective, production management systems must tell us what we should do and what we can do, so that we can decide what we will do, then compare with what we did to improve our planning.


Neither complicated, nor complex. Snowden describes that in the simple domain, cause-effect relationships (1) exist, (2) they are predictable, and (3) they can be determined in advance. In simple systems, that relationship is self-evident to any reasonable person, as a result, a manager can Sense-Categorize-Respond: we see what is coming in, we make it fit predetermined categories and we decide what to do, that is, we apply best practice. → as distinct from complicated or complex Reference: Snowden, D.J. and Boone, M.E. (2007). “A Leader’s Framework for Decision Making.” Harvard Business Review, Nov., 69-76.

Single Minute Exchange of a Die (SMED)

Refers to a stretch-goal set by Toyota (i.e., changing dies in less than 10 minutes rather than hours) that aims at driving down the setup time required when changing out dies. Reduced setup times makes load leveling (heijunka) more palatable.


→ see Short Interval Planning System

size [LPS]

A quality criterion in the Last Planner System whereby the amount of work included in an assignment is made to match the capacity of the production unit that will do the work. Example: Ruben and James should be able to collect that data and analyze it by Thursday. But, I forgot, it’s Ruben and Tim. Tim’s not as experienced as James, so I’d better give them an extra day.

small wins

Related to continuous improvement, recognition that any gain (win) is a gain (win) and therefore worth pursuing. In addition, the practice of identifying and implementing small wins increases awareness additional opportunities for small wins. References: Akers, Paul A. (2011). 2 Second Lean: How to Grow People and Build a Fun Lean Culture. FastCap LLC, 176 pp., Ambile, Teresa and Kramer, Steven J. (2011). “The Power of Small Wins.” Harvard Business Review. May.


→ see Single Minute Exchange of a Die

sound(ness) [LPS]

A quality criterion in the Last Planner System that questions whether or not assignments have had all constraints removed.

Example: We never intentionally make assignments that are not sound. We always check if we have or can get necessary information from others, if the directives are clear, etc.

source inspection

The practice of constantly monitoring a process for any occurrence of an error. Should one be detected, production must be stopped to correct it or measures must be taken to prevent the error from becoming a defect. The likelihood of an error occurring may be reduced by using poka yoke or mistakeproofing. Concept developed by Shigeo Shingo in the 1960s, in pursuit of the goal “Defects = 0 is absolutely possible!” Shingo (1986 p. 82) stated: “I claim that it is impossible to eliminate all errors from any task performed by humans. Indeed, inadvertent errors are both possible and inevitable. Yet errors will not turn into defects if feedback and action take place at the error stage. In this way, I am advocating the elimination of defects by clearly distinguishing between errors and defects, i.e., between causes and effects.” Related → see self-inspection Related → see poka yoke or mistakeproofing Reference Shingo, Shigeo (1986). Zero Quality Control: Source Inspection and the Poka-yoke System. Productivity Press, Cambridge, MA, 303 pp.

spaghetti chart

A diagram of the path taken by a product as it travels through the steps along a value stream. So called because in a mass production organization the product’s route often looks like a plate of spaghetti.

Source: visited 9 March 2015

(to) specialize

Process whereby production units—individuals or groups—acquire skills and techniques that no other production unit has.

→ also see (to) multiskill


Description of what is required (requirements) to meet a customer’s Conditions of Satisfaction.

stacked bar chart [TP]

Synonymous with operator balance chart, cycle time diagram, or Yamazumi chart. A stacked bar chart shows the cycle time for each step in a process (or operation), distinguishing within each cycle time its value-added component from its non-value added component. It is a visual tool that shows which steps can be done within or exceed the takt time and which cycle time may be improved.

Reference: After visited 2022-04-17


An agreed-upon reference or baseline from which deviation is observed and measured. Any standard is implied to be a current-best standard that can be improved upon and replaced by a better standard.

standard(ized) work

Agreed-upon process for performing work, used repeatedly, and serving as the baseline from which to measure improvements.


Process of limiting variety.

standardization of parts

Decision to repeatedly use parts with the same characteristics (size, material, functionality, etc.).

(to) starve

A process starves when it is missing an input or does not have anything to process.


Unit of work in an operation that is taken by a production unit. It can be broken down further into elemental motions.

(to) stock out

Running out of something that is needed and usually kept in inventory (stock).

stretch goal

Goal that requires the performer, individual or group, to perform beyond their current best practice.

successive inspection

Inspection performed by the immediate customer of a process, principally focused on their own conditions of satisfaction. May include technical inspectors who take into account all quality conditions.


That which comes later (succeeds) in time. → inverse of predecessor


Holding place for in-process inventory that is limited in size. Illustration → see kanban


The provider of needed inputs: prerequisites (including materials and information), resources, and directives.

→ also see activity definition model G_supplier Task that transforms supplier input using performer resources into customer output.

supplier lead time

[unit of time] The time from sending a request for delivery to the delivery. → see lead time

supplier managed inventory, vendor managed inventory (VMI)

Inventory that is located at the customer’s location but managed by the supplier.

Supply Chain Management (SCM)

The practice of a group of companies working collaboratively in a linked chain (network) of interrelated processes designed to best satisfy end-customer needs while rewarding all members of the chain. Reference: Tommelein, I.D., Walsh, K.D., and Hershauer, J.C. (2003). Improving Capital Projects Supply Chain Performance. Research Report PT172-11, Construction Industry Institute, Austin, TX, 241 pp.

sustainability, sustainable development

Meeting the needs of the present without compromising the ability of future generations to meet their own needs. Reference: term coined in the report Our Common Future by the Brundtland Commission in 1987.

Suzuki’s YET

The practice of automotive engineer Ichiro Suzuki (1937-present) at Toyota of trying to meet (seemingly) conflicting design criteria when developing the first Lexus. In other design practices, conflicting criteria (or corresponding design features) are traded off against one another, or considered mutually exclusive. Suzuki's YETs involve disqualifying accepted engineering solutions to design problems encountered in trying to beat exceed performance benchmarks.

Example: We must have both a super quiet and light weight car, so we can't use mass to absorb vibration. We must attack vibration at its source; i.e., the engine.

swimlane diagram, multi-functional diagram

→ see cross-functional diagram




→ see Tasks Anticipated


Tabular Method [CBA]

A method for Choosing By Advantages, especially for complex decisions.

Step 1: Gather all relevant stakeholders and determine impasse resolution method.
Step 2: Choose alternatives likely to yield important advantages.
Step 3: Define factors to evaluate the alternatives.
Step 4: Define must criteria and want criteria for each factor.
Step 5: Identify attributes of each alternative that speak to the criteria.
Step 6: Underline the least preferred attribute in each factor by criterion (row by row).
Step 7: Calculate advantages for each factor by comparing each attribute to the least preferred attribute.
Step 8: Circle the most important advantage for each factor/criterion.
Step 9: Choose the paramount advantage among all the most important advantages (circled in step 8).
Step 10: Assign the maximum importance score to the paramount advantage.
Step 11: Assign importance scores to the most important advantages based on the paramount advantage.
Step 12: Assign importance scores to the other advantages based on the most important advantages and the paramount advantage.
Step 13: Sum importance scores for each alternative.
Step 14: Evaluate cost data if applicable.


takt, takt time

[unit of time]

Takt is the German word for “beat,” referring to the regularity with which something gets done.

It is the maximum unit of time within which a product must be produced (supply rate) in order to match the rate at which that product is needed (demand rate).


If you have a total of 8 hours (480 minutes) in a shift (gross time) and subtract 30 minutes lunch, two 15 minutes breaks, 10 minutes for a team briefing, and 10 minutes for basic maintenance checks, then the net time available to work = 480 min – 30 min – 2 * 15 min – 10 min – 10 min = 400 min.

If customer demand was, say, 400 units per day and you were running one shift, then the takt time must be set at 1 minute. Your line would be required to produce one unit every minute in order to be able to keep up with customer demand.


Takt Time Planning (TTP)

Use of takt time in the course of work structuring in order to develop a (phase) plan with smooth work flow..


Target Cost (TC) [TVD]

[units of money]

In Target Value Design, the cost that a project team is striving to achieve, either less than or equal to the allowable cost, and typically a stretch goal relative to previous performance capability.

Note that the project target may be set in terms of scope: to deliver more value for a given cost.


Target Value Design (TVD)

The practice of defining scope, performance goals, and target cost in advance of starting design, and then steering the design and construction process so as to meet all.

Macomber and Barberio (2007) coined the term “target value design” proposing practices different from conventional project management namely:

“Rather than estimate based on a detailed design, design based on a detailed estimate.
Rather than evaluate the constructability of a design, design for what is constructable.
Rather than design alone and then come together for group reviews and decisions, work together to define the issues and produce decisions then design to those decisions.
Rather than narrow choices to proceed with design, carry solution sets far into the design process. [in other words, practice set based design]
Rather than work alone in separate rooms, work in pairs or a larger group face-to-face.”

Macomber, H. and Barberio, J. (2007). “Target-Value Design: Nine Foundational Practices for Delivering Surprising Client Value.” Lean Project Consulting, Inc.,, self-published, 3 pages.
Tommelein, I.D. and Ballard, G. (2016). Target Value Design: Introduction, Framework, and Current Benchmark. P2SL Report, Project Production Systems Laboratory, University of California, Berkeley, CA, March, 51 pp.


task [LPS]

Description of a part of an activity as it gets exploded into smaller pieces (boulder – rock – pebble – grain/dust) in the make-ready planning process to address the concern of making means meet ends (e.g., by operation design in first run studies).

Specific type and amount of work assigned to a production unit that the production unit can commit to performing.


Tasks Anticipated (TA) [LPS]

A lookahead metric in the Last Planner System that gauges the percentage of all tasks in a plan for a target week, that were anticipated in an earlier plan for that target week.

TA is the ratio of the number of tasks common to two sets of tasks, one set further out from- and the other closer to the tasks' execution time, to the total number of tasks in the set closer to execution. These sets could be any number of time periods apart, in general TAj-to-i

Together with Tasks Made Ready (TMR) it characterizes the ability of the planning team to make work ready.

Example: Assume today is June 2.

The plan for June 5-9 in the 4-week LOOKAHEAD May29-Jun23, was labeled WEEK 2 as it was two weeks prior to execution. It consisted of the set of tasks A, B, C, D, E, and F. The plan for that same week, June 5-9, but updated one week later as shown in the 4-week LOOKAHEAD Jun05-Jun16, is now labeled WEEK 1 as it is one week prior to execution. It consists of the set of tasks B, D, E, G, and H. Thus, 3 tasks appear in both sets, namely B, D, and E.

Accordingly, TA2-to-1 = BDE/BDEGH = 3/5 = 60%.
In other words, 60% of the tasks in a later plan for the target week were anticipated in an earlier plan for the week.

Accordingly, TMR2-to-1 = BDE/ABCDEF = 3/6 = 50%
In other words, 50% of the tasks in an earlier plan for the target week were made ready in the later plan for that week.

Note: PPC = TMR1-to-0


Image by Iris D. Tommelein, all rights reserved, (c) 2016.


Tasks Made Ready (TMR) [LPS]

A lookahead metric in the Last Planner System that gauges the percentage of all tasks in a plan for a target week, that are included in a later plan for that target week. It describes the ability of the plan(ner) to forecast (predict) accurately at one point in time what tasks will take place at another point in time in the future.

TMR is the ratio of the number of tasks common to two sets of tasks, one set further out from- and the other closer to the tasks' execution time, to the total number of tasks in the set further out. These sets could be any number of time periods apart, in general TMRj-to-i

Together with Tasks Anticipated (TA) it characterizes the ability of the planning team to make work ready.

Example and illustration → see Tasks Anticipated (TA)



→ see Target Cost

Transformation Flow Value, TFV theory of production

Theory of production that recognizes three competing schools of thought exist in production management:

  1. the transformation view (predominant in Project Management),
  2. the flow view, and
  3. the value view.

In lean construction, all three are pursued at the same time.

Reference: Koskela, L. (1992). Application of the New Production Philosophy to Construction. Technical Report 92, CIFE, Stanford University, Stanford, CA.


Image source: Iris D. Tommelein



[unit of product/unit of time]

The output rate of a production process. The number of units that are produced in a stated period of time.



→ see Tasks Made Ready



Range of variation permitted in a specified dimension or location (1D, 2D, or 3D) without impacting structural integrity, operating capability, or abutting components (after CII 1993). This definition pertaining to geometry equally applies to any material, resource, or process property such as duration, temperature, impact strength, etc.

Reference: CII (1993). Constructability Implementation Guide. CII Special Pub. 34-1, Univ. of Texas, Austin, TX.


total time

[unit of time]

Time (lead time, cycle time, or both) computed as the sum of value-added time (VAT) plus non-value added time (NVAT) in a process.


Toyota’s 14 Principles

→ see Principles of the Toyota Way



Toyota Production System; Thinking People System.

Reference: Ohno, T. (1988). The Toyota Production System: Beyond Large-Scale Production. Productivity Press, Portland, OR. 143 p.


transfer batch

→ see batch



The conversion (changing of characteristics) of an input into an output.



One of 7 wastes defined by Ohno (1988) referring to unnecessary movement of products and materials. This may be reduced by one-touch handling: lifting materials off the truck and positioning them in their final location without rehandling (no laydown or staging).


true north

The ideal or a set of principles that a business sets out to strive for.



→ see Target Value Design


Two-list Method [CBA]

A method in the decisionmaking system called Choosing By Advantages, used to choose one of two alternatives.




Lack of knowledge.



Making assignments to a production unit or resource within a production unit that absorbs less than 100% of its capacity; that is, creating a capacity buffer. Underloading is necessary to accommodate variation in processing time or production rate, in order to assure plan reliability. Underloading is also done to release time for workers to take part in training or learning, conducting first-run studies, implementing process improvements, or for equipment to be maintained.



The percentage of a resource’s capacity that is used in production. Example 1: Because of time lost waiting for materials, our labor utilization last week was only 40%. Example 2: We deliberately reduced next week’s planned labor utilization rate so crew members could attend a training course.





The state of a resource (e.g., worker or production unit) when it is not in use (could be use in production or maintenance). One of 7 wastes.



Anything with a cost of any kind, the elimination of which does not reduce value delivered. → see 7 Wastes, muda, muri, mura


Weekly Work Plan, Commitment Plan [LPS]

A list of quality assignments to be completed within the specified time period that have been reviewed and committed to by the last planner; typically committed as near as possible to the beginning of that time period (a weekly work plan is a plan with commitments that span one week). Master-, phase-, and lookahead (or make-ready) plans of course also must have activities that people commit to performing! The list should be produced 2-3 weeks (or other lead time deemed necessary) before commitment in order to identify and remove constraints and to measure success in making ready.


Whole Life Target Value Design [TVD]

Target Value Design pursued while taking into account not only Design, Construction, and Operations and Maintenance, but also Business Costs and Outcomes. → see Target Value Design


window of plan reliability

How far in advance future work completions are predictably forecast.

Example: If you can predictably forecast only 1 day in advance when work will be completed, then your window of reliability is 1 day.



→ see work-in-process


work balancing, work load balancing

Reassigning work that was assigned to one individual or production unit to be done by another individual or production unit in order to even out the amount of time each needs to complete their work. Related → see load leveling


work density [TP]

[unit of time / unit of area]

Work density is a trade-specific project characteristic that compiles the outcomes of a many production system design decisions. It is defined as the time a trade will require to do their work in a certain area, based on:

  1. Product design (i.e., What is shown in the construction project drawings and specifications?),
  2. Scope of the trade’s work (i.e., Where are the trade jurisdictional boundaries and contractual agreements?),
  3. Specific steps of the operation in their schedule (depending on work already in place and work that will follow later in the same or another process),
  4. Means and methods the trade will use (i.e., How will work be done? E.g., increasing prefabrication off-site will tend to lower the work density on-site.),
  5. Accounting for crew capabilities and size (i.e., Who will do the work? What are their skills, levels of technical understanding, etc.?).

For example in construction, the dimensional units may be hours/m2 or days/m2.


work flow

The movement of information and materials through a network of production units, each of which processes them before releasing to those downstream.


work flow control

Causing information or materials and assignments to move through a network of production units in a desired sequence and at a desired rate.


work load

→ see workload


work structuring

Process of breaking work into pieces, where pieces will likely be different from one production unit to the next, so as to promote flow and throughput. Work structuring answers the following questions (Ballard 1999, Tsao et al. 2004):

  1. In what units will work be assigned to groups of workers?
  2. How will work be sequenced?
  3. How will work be released from one group of workers to the next?
  4. Will consecutive groups of workers execute work in a continuous flow process or will their work be decoupled?
  5. Where will decoupling buffers be needed and how should they be sized?
  6. When will different units of work be done?

Work structuring is a dynamic process to be re-evaluated in the course of a project. At the project onset, work structuring deals with designing the overall system. As the project progresses, work structuring becomes more focused to guide the design and execution of interacting pieces of impending work. References: Ballard, G. (1999). “Work Structuring.” LCI White Paper-5, June. Howell, G., Laufer, A., and Ballard, G. (1993). “Interaction between Subcycles: One Key to Improved Methods.” ASCE, J. Constr. Engin. Manage., 119 (4) 714-728. Tsao, C.C.Y., Tommelein, I.D., Swanlund, E., and Howell, G.A. (2004). “Work Structuring to Achieve Integrated Product-Process Design.” ASCE, J. Constr. Engin. Manage., Nov/Dec, 130 (6) 780-789.


workable backlog [LPS]

In the Last Planner System, assignments that have met all quality criteria, except that some must yet satisfy the sequence criterion by prior execution of prerequisite work already scheduled. Other backlog assignments may be performed within a range of time without interfering with other tasks. Workable backlog can be used when capacity becomes available during execution of a work plan (e.g., when some work on a weekly work plan cannot be executed for some reason).

Example: Those spare parts lists don’t have to be completed for 3 months, but it won’t harm anything if they are produced earlier, so use them as fallback or fill-in work when needed.


work-in-process (WIP)

The units or quantities of materials between the start and end points of a production process.

Illustration → see inventory


workload [TP]

The amount of time (cumulative work density) a trade specialist needs to complete a certain process step in a process in a certain part of a work area (zone).




Yamazumi chart [TP]

A Yamazumi chart is a cycle time histogram or stacked bar chart.

see → stacked bar chart



zero quality control (ZQC)

Quality practices aimed at achieving zero defects and therefore eliminating the need for ad-hoc control. It is based on the recognition that people will make mistakes and the principle that defects can be prevented by controlling the performance of a process (preventing any mistake from becoming an defect), e.g., using techniques such as mistakeproofing aka. poka yoke).

Reference: Shingo, Shigeo (1986). Zero Quality Control: Source Inspection and the Poka-Yoke System. Taylor & Francis.


zone [TP]

In takt planning (aka. takt time planning), a delimited space where one production unit gets scheduled to complete a certain scope of their work within the takt time.