Product Development Cadence

Definition

Cadence is product development's equivalent of manufacturing takt time: a chosen, steady rhythm — a set new-product introduction rate — that synchronizes activity across an entire development portfolio instead of letting each project run on its own optimized schedule. Applying Little's Law from queuing theory (N = λT), Oosterwal derives development throughput as TH = WIP / CT: the rate of new-product introduction is set by how much work-in-process the portfolio carries divided by how long each project takes to complete. Optimizing individual projects tends to suboptimize the whole portfolio; a shared cadence does the reverse.

In the Book

Chapter 6 traces the idea to Thomas Edison's "invention factory," where Edison targeted a minor invention every ten days and a major one every six months rather than leaving invention to chance — the discipline of an output rate, not raw genius, drove Menlo Park's productivity. At Harley-Davidson, engineering planner Anthony Reese operationalized cadence by classifying every project as small, medium, or large ("bins") based on historical engineering-budget data, fixing each bin's resource allocation, and locking completion to the annual July dealer show. Fixing scope, schedule, and resources this way turned a chaotic mix of projects into standard categories that could be aggregated and planned. The book contrasts this with what happened during the Beavertail crisis, where giving one troubled project head-of-the-line privileges optimized that single project while halting many others — the same whipsaw dynamic Little's Law predicts when WIP is allowed to bunch unevenly across a shared resource pool.

Why It Matters

This gives portfolio-level leaders a quantitative lever — throughput as a function of WIP and cycle time, not a target to be willed into existence — and a reason to say no to individually-attractive projects: adding to WIP without adding capacity slows every other project in flight. It applies wherever multiple efforts share a fixed resource pool (a research portfolio, a hiring pipeline, a shared engineering team across product lines): a deliberate, organization-wide cadence beats the sum of locally-optimized schedules.