‘Poka Yoke’ or Quality by Mistake Proofing Design and Construction Systems

Iris D. Tommelein1

1Director, Project Production Systems Laboratory, http://p2sl.berkeley.edu/, and Professor, Engineering and Project Management Program, Civil and Environmental Engineering Department, 215-A McLaughlin Hall, University of California, Berkeley, CA 94720-1712, Phone +1 510/643- 8678, FAX +1 510/643-8919, [email protected]


The Japanese concept ‘poka yoke’, translated into English as ‘mistake proofing,’ has been mentioned at previous IGLC conferences. This notwithstanding, mistake proofing appears to not have been (nor be) systematically researched or practiced in the lean construction community. To raise awareness of opportunities provided by thinking with mistake proofing in mind as a means to build quality into project delivery, this paper summarizes the philosophy that underlies mistake proofing. Examples illustrate how mistake proofing applies to the work done within one specialty trade, how manufacturers and fabricators can design their products so they cannot be constructed defectively, and how architects and engineers may conceive of system designs that are less likely to fail during construction or in a product’s life cycle. Reader contributions to an online repository of mistake proofing applications in the architecture-engineering-construction (AEC) industry, posted at http://p2sl.berkeley.edu/pokayoke/, will be gratefully acknowledged.


poka yoke, mistake proofing, jidoka, autonomation, design, engineering, system, specification, construction, safety, quality, constructability, tolerance management, life-cycle performance, lean construction



Tommelein, I. D. 2008. ‘Poka Yoke’ or Quality by Mistake Proofing Design and Construction Systems, 16th Annual Conference of the International Group for Lean Construction , 195-205. doi.org/

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