"Concurrent Development" is an essay on lean-essays-blog exploring concurrent development approaches, drawing on allen-ward's research into Toyota's set-based concurrent engineering and connecting it to software development practice.
Argument
The essay argues that set-based-design — exploring multiple design alternatives simultaneously rather than converging early on a single solution — is not a sign of indecision but a rational strategy for managing uncertainty in complex development work. Ward's research on Toyota's product development system showed that this approach, counterintuitively, produced faster time-to-market with higher quality than the point-based approaches common in Western engineering. The Poppendiecks extend this argument to software, where the cost of reversing a premature design decision can be substantial.
The essay connects set-based-design to the decide-as-late-as-possible principle: deferring design decisions until the last-responsible-moment is only feasible if multiple options are being developed concurrently. The two concepts are structurally linked — concurrent development is the practice that makes late decision-making economically viable.
Context
This essay reflects the influence of the University of Michigan's Japan Technology Management Program — where Allen Ward, jeffrey-liker, Durward Sobek, and others conducted the foundational research on Toyota's product development practices — on the Poppendiecks' thinking. The translation of set-based concurrent engineering from physical product development to software is one of the Poppendiecks' more technically demanding translations, requiring careful attention to what "design options" means in a software context and what it costs to maintain multiple alternatives.