Toyota's Principles of Set-Based Concurrent Engineering

The design and development system of Toyota Motor Corp. contributes greatly to the firm's remarkably consistent growth in market share and its enviable profit per vehicle. This article, which extends the author's previous study of the Toyota product development system, reports on further data collection in Japan and at the Toyota Technical Center in Michigan. Findings substantiate the authors' previous claims about the product development system and lead them to conclude that Toyota is set-based in its approaches. Set-based concurrent engineering (SBCE) begins by broadly considering sets of possible solutions and gradually narrowing the set of possibilities to converge on a final solution. The SBCE idea is developed through 3 principles that guide Toyota's decision making in design: 1. simultaneous mapping of the design space according to functional expertise, 2. integration by intersection of mutually acceptable functional refinements introduced by the design and manufacturing engineering groups, and 3. establishment of feasibility before commitment.