The Principles of Product Development Flow

What Hacker News says

1. wreathJun 2026
   I don't think this is a good resource for an intro tbh. Unless you are interested in proofs and have some probability basics covered, it feels quite dense.

   I liked Principles of Product Development Flow a lot more because it was easier to digest, although it's a different application of queuing theory.

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2. tomeApr 2026
   Do you have any recommendations? I find his book Principles of Product Development Flow very interesting.
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3. thisoneisrealJul 2025
   The point about task variability being normal, and attempts to reduce variability being destructive, is explained exceptionally well in "The Principles of Product Development Flow." Metrics folks want software engineering to have units of work so that it can be measured like an assembly line, or sales, or any other number of things that make sense to quantify. But the reality is that we build and make adjustments to interconnected systems, and that just can't be reduced to arbitrary units. Tasks are heterogeneous and work on different scales. When you try to cram them all into the same sized box, you are actually creating friction and making the problem worse.
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4. wry_durianJun 2025
   Cycle time is imprtant, but three problems with it. First, it (like many other factors) is just a proxy variable in the total cost equation. Second, cycle time is a lagging indicator so it gives you limited foresight into the systemic control levers at your disposal. And third, queue size plays a larger causal role in downstream economic problems with products. This is why you should always consider your queue size before your cycle time.

   I didn't see these talked about much in the paper at a glance. Highly recommend Reinertsen's The Principles of Product Development Flow here instead.

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5. asplakeMay 2025
   The product vs engineering framing here didn’t sit well with me. For a deep dive I would recommend Don Reinertsen’s Principles of Product Development Flow (2009).
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6. code_biologistApr 2025
   Agreed! The Principles of Product Development Flow by Donald G. Reinertsen[1] is one of my favorite product management books because it's very conceptual, but man the concepts hit home fast. This summary has a lot of great details [2] and the third chapter is entirely dedicated to the properties of queues.

   After, Little's law, he introduces the First Queue Size Control Principle (Q13): Controlling queue size rather than capacity utilization offers a more effective way to manage cycle time and process efficiency. — No mister business stakeholder, adding items to the dev team's to-do list and making sure they are working 110% isn't going to get stuff delivered faster.

   Diffusion Principle (Q15): Random processes can lead to queues spinning out of control; these high-queue states can last long and cause significant economic damage. — No mister business stakeholder, we can't fix this one little thing right now, it's bigger than you think and is going to make it harder to deliver the big important project.

   [1] https://www.amazon.com/Principles-Product-Development-Flow-G...

   [2] https://www.joecotellese.com/posts/principles-of-product-dev...

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