Takt Time Planning (TTP)

Takt Time Planning (TTP) Initiative

What is Takt Time Planning?

The German word ‘Takt” refers to a “beat” (as in music), that is, to the regularity with which something gets done. Takt time sets the heart of production lines at Toyota. Takt is a design parameter used in production settings (be it manufacturing, construction, or other). Hopp and Spearman (2008), define “Takt time is the 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).” 

Takt time basically sets the pace for the work flow of (sub)contractors making up a “Parade of Trades” (Tommelein et al. 1998) or, more generally, progressing through space according to desired patterns of flow.

Takt serves as a work structuring method: using takt time means introducing regularity in time-space to work planning. This regularity presumably alleviates the crews from the need to spend resources to plan when they will work where, so they have more time to focus on work planning (how will they do the work, what are the best means and methods, resources needed, …?) and shared resource planning (e.g., man-lifts, access paths, etc.)

Sample Research Questions

  • How to determine what a takt time and associated work areas (zones) should be, given a project’s (or phase, or other part) certain scope of work. This determination of time and space will vary based on the nature of the work to be done. What else is to be considered? How to manage work-load imbalances? What if trades do not follow a Parade? How to explore alternative choices?
  • How to capture the way in which trades conceive of their assigned scope and plan their work?
  • What to buffer? What to capacities to underload? (In traditional project management, the focus is on optimizing individual resource utilization. With takt-time planning this is not the (exclusive) focus; the focus is on overall system design and performance optimization (utilization, robustness, resilience, etc.).
  • How to reconcile the way trades plan their work (work breakdown structures, activity codes, or whatever is used by the trade) with the way the project gets planned at higher levels?
  • How to represent the takt-time plan to all involved? For use during execution and control? Using BIM or not?
  • Where does Takt-time planning ‘fit’ in the Last Planner(r) System? Possibly prior to phase scheduling?
  • Takt-time planning is in many ways akin to production system design. This raises questions about how the design of the facility affects the definition of the takt time and corresponding zones, vs. how a design may be created in order to allow for effective use of takt times and zones.
  • How can we explore the alternatives using BIM, simulation, or other tools?

Can work that is done in project production systems also be defined with a heart beat and what would the benefits of that be; why not simply schedule it?

NSF Funded Research on Takt Time Planning

Research to study the “Theory and Application of Takt-time Planning in Project-based Production” is being funded by a 3-year grant from the National Science Foundation (award number 1563511).

Abstract

A new conceptualization for planning and delivering Architecture-Engineering-Construction (AEC) projects is needed because today’s approaches all too often fail: projects are late, over budget, and accident prone. This unduly burdens public and private facility owners, other stakeholders, and society at large. Failure stems from the inadequacy of the planning methods being used, especially those that focus disproportionately on maximizing resource utilization while ignoring network effects and the systemic impacts of variability.

This research counterposes a method based on Takt time. Takt refers to the beat with which work progresses; it is being used successfully in repetitive manufacturing (e.g., Lean Production). The use of Takt time in AEC project production is novel. The method has been piloted and is promising, but must be formally studied.

This award supports fundamental research that involves designing, analyzing, and testing principles, methods, and computational optimization tools for Takt time planning (TTP). The objective of this method is to optimize project delivery speed within total cost limits, and to provide a mechanism for continuous improvement. Investigation of the potential uses of the TTP method to improve project delivery performance will advance the theory of project production. Use of the new planning model, once formulated, understood, and documented, will increase the reliability with which projects get delivered, to the benefit of all stakeholders.

Students underrepresented in science, technology, engineering, and mathematics will be engaged in conducting this research. Research findings will be integrated into engineering curricula and disseminated to industry to promote the use of more systemic methods for planning and delivering facilities.

Existing planning models focus on maximizing resource utilization (point speed) and buffer for uncertainty using time (schedule buffers), which comes at the expense of throughput. This research flips the paradigm used in existing planning methods to one that focuses on overall project delivery performance and buffers with capacity. Planning using capacity means judiciously under-loading production resources, such as labor and equipment, to less than 100% utilization, so that they will have stand-by capacity to readily mitigate negative impacts of variation, thereby avoiding system-wide repercussions.

Accordingly, a novel method for project planning will be designed and developed, based on the concept of Takt time. Computer algorithms will be created to automate the determination of zones and corresponding Takt times, suited to characteristics of various phases of project delivery. Their optimality and robustness will be established using Building Information Modeling (BIM) and discrete-event simulation. In parallel with the virtual study of TTP, the method will be deployed on actual projects so as to reveal socio-technical system characteristics that must be addressed for its successful deployment. Learning from actual projects will in turn inform further refinement of algorithms.

References

Frandson, A., Berghede, K., and Tommelein, I.D. (2013). “Takt Time Planning for Construction of Exterior Cladding.” Proc. 21st Annual Conf. of the Int’l. Group for Lean Constr. (IGLC 21), Fortaleza, Brazil.

Frandson, A. and Tommelein, I.D. (2014). “Development of a Takt-time Plan: A Case Study.” In Castro-Lacouture, D., Javier Irizarry, J., and Baabak Ashuri, B. (eds.). Proceedings of the Construction Research Congress 2014: Construction in a Global Network, Atlanta, Georgia, 19-21 May 19-21, ASCE, pp. 1646-1655. doi: 10.1061/9780784413517.168

Frandson, A.G., Seppänen, O., and Tommelein, I.D. (2015). “Comparison Between Location Based Management and Takt Time Planning.” Proc. 24th Ann. Conf. of the International Group for Lean Construction (IGLC 24), Boston, MA, July.

Frandson, A. and Tommelein, I.D. (2016). “Takt time planning of interiors on a pre-cast hospital project.” Proc. 24th Ann. Conf. of the International Group for Lean Construction (IGLC 24), Boston, MA, July, online at http://www.iglc.net/Papers/Details/1339

Hopp, W. and Spearman, M. (2011). Factory Physics: Foundations of Manufacturing Management. 3rd edition, Waveland Press.

Linnik, M., Berghede, K., and Ballard, G. (2013). “An Experiment in Takt Time Planning Applied to Non-repetitive Work.” Proc. 21st Annual Conf. of the Int’l. Group for Lean Constr. (IGLC 21), Fortaleza, Brazil.

Tommelein, I.D., Riley, D., and Howell, G.A. (1999). “Parade Game: Impact of Work Flow Variability on Trade Performance.” ASCE, J. of Constr. Engrg. and Mgmt., 125 (5) 304-310, Sept/Oct.