UC Berkeley

This study set out to investigate and document how the principles and practices of so-called mistakeproofing may be applied to improve safety and health performance—aspects of product and process quality—specifically in the construction industry. Mistakeproofing (translated from the Japanese word poka yoke, a concept integral to the Toyota Production System, defined as Lean) has been successfully used in numerous other industry sectors. It can be used likewise in the construction industry. A strength of Lean is its conceptual clarity on principles and the associated systems thinking it promotes. In addition, supporting the principles are numerous tools and methods (such as mistakeproofing), to be applied judiciously in any given system’s context and, when used in combination, leveraging one-another. The research defined the Lean principles of mistakeproofing, and also the principles of TRIZ (Theory of Inventive Problem Solving) used for concept generation. Thirty examples, collected by reading the literature and interviewing industry practitioners, were catalogued based on the mistakeproofing and TRIZ principles they illustrate. The need to mistakeproof everyday products and processes (tasks and work methods) may seem obvious (or hopefully will appear obvious in hindsight), but mistakeproofing is by no means a common practice. By defining the principles and offering examples, this report aims to encourage broader awareness and use of it. Knowledgeable and purposeful use of mistakeproofing principles and their practical application will lead to improved industry performance in construction, as it has in other industries.