Knowledge Center > Glossary > N


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