Jeffrey Liker is an industrial engineering professor at the University of Michigan and author of "The Toyota Way" (2004), which codified Toyota's management system into 14 principles organized across four categories: long-term philosophy, the right process, people and partners, and continuous learning. His work, alongside james-womack's manufacturing-focused lean, represents one of the primary streams of Toyota research that shaped the broader lean movement.
The Toyota Way and Its Relationship to Lean Software
Liker's 14 principles extend beyond the production floor lean that Womack and Jones focused on, addressing Toyota's management philosophy, supplier relationships, and learning culture. Several of these principles — particularly the attention to long-term thinking over short-term results, the emphasis on learning through direct observation, and the practice of building in quality rather than inspecting it in — resonate with the Poppendiecks' framework in ways that go beyond the manufacturing-process translations.
"The Toyota Way" reached a wide management audience in 2004, the same year the Poppendiecks' first book was being widely read. The parallel publication timing reinforced each other: readers encountering lean software development could deepen their understanding of Toyota's system through Liker's comprehensive account.
Collaboration with Allen Ward
Liker's most direct relevance to the Poppendiecks is through his collaboration with allen-ward on the University of Michigan's Japan Technology Management Program. Together, Liker, Ward, and Durward Sobek conducted the research on Toyota's product development practices that produced the set-based concurrent engineering framework. Liker's access to Toyota and his research infrastructure helped make Ward's deeper investigation of product development practices possible. The 1999 MIT Sloan Management Review paper documenting Toyota's set-based principles — the primary source for the Poppendiecks' set-based-design concept — carries all three authors.