The Principles of Product Development Flow


Lean Product Development


30 second summary


Developing products is not that dissimilar to manufacturing – both seek to perform a series of tasks as effectively as possible. Many of the methods used to improve a manufacturing process can be applied to product development, and this book is perhaps the best resource for learning these methods. It’s a pretty difficult read (it’s very technical, has equations, and can be pretty intimidating at times), but the author is a true expert on this stuff and the concepts — when distilled and clarified — are not overly complex.


2 more minutes of summary


This book has eight major themes.

1. Economics
The rationale behind any decision in product development should be ECONOMIC. Going faster, slower, adding or removing a feature…all should be considered for their economic value. Don (the author…I’m using Don since Reinertsen is a pain in the ass to type) boils this down to a fairly simple question: how much will a delay in product development cost you in revenue and profit?

2. Queues
In product development, our greatest waste is not unproductive engineers, but work products sitting idle in process queues.” Queues sound complex – at least they did to me. I am intimidated by the term “Queueing theory.” Just think about waiting in a line; nobody likes to do that and it wastes time.

3. Variability
Another slightly scary term, especially when the author says that this concept is very misunderstood in product development. Creating new products means doing something original. That involves unknowns, uncertainty, and risk. This book can help you manage that stuff.

4. 5. and 6. Batch size, WIP constraints, and Cadence, Synchronization, and Flow Control
Holy shit. Did you see those complex words? Fret not. Basically all of these concepts are related to efficient manufacturing, but all can be applied to developing products more efficiently. Actually, Don wouldn’t really like me to use “efficiently” here because maximizing efficiency is not the goal; the goal is economic (profit) and product development processes should maximize profit, not efficiency.

7. Fast Feedback
Covers the basic idea of failing fast and early, but in a more rigorous a.k.a. deep manner. Connects feedback and economics, i.e. Don explains how you can generate useful information quickly in order to make better decisions.

8. Decentralized control
Another concept taken from lean manufacturing, allowing decisions to be made at the appropriate level is key to moving faster and improving efficiency.


Just a few posts right now…I’m working on more!