by Leon Rosenshein

Let It Flow

Like many things, I’ve talked about Flow and WIP before. The idea that what you want to optimize for is getting things done, not doing things. That’s a pretty subtle difference, but it’s an important one.

Or as it was said in Principle of Product Development Flow,

In product development, our problem is virtually never motionless engineers. It is almost always motionless work products.

– Donald Reinertsen

So much of how we work is designed to keep us busy. Blocked on waiting for someone else to do something? Start another task. Waiting for some tests to run? Start refactoring your code. Whatever you do, don’t just do nothing.

Now to be clear, I’m NOT recommending you sit around and do nothing if you can’t work directly on whatever it is you’re doing. That is not going to help.

But instead of doing nothing or starting the next task, maybe help the person you’re waiting for. They might get done sooner, which helps them get back to what they were supposed to be doing. Even if it makes things take a bit longer, the next time you’re in that situation you won’t need to bother them. You won’t be blocked, and they won’t be interrupted. Better for everyone.

Or another typical case. You need to run an integration test. It takes 20 minutes, so as soon as you start it, you go do something else. It takes you 15 minutes to context switch and get back up to speed. Just as you start getting somewhere, the test finishes. But you don’t notice because you’re busy. 10 minutes later you notice and go back to the first task. After another 15-minute context switch. You’re back to where you were before the test started. Think about it. You just spent 40+ minutes (2 context switches and a bit of time actually working) for 10 minutes of progress. Do that 3 or 4 times a day and you’ve wasted way more time than you’ve been productive.

Another quote from the book is

Since high capacity utilization simultaneously raises efficiency and increases delay cost, we need to look at the combined impact of these two factors. We can only do so if we express both factors in the same unit of measure, life-cycle profits. If we do this, we will always conclude that operating a product development process near full utilization is an economic disaster.

I know there are a lot of management buzzwords in there, and SAFe has picked up on this quote in particular, but that doesn’t mean it’s wrong. Like most things engineering, it’s a trade-off, and the answer always starts with “It depends …”. And with all trade-offs, the way to make it is to understand what you’re trading off against something else, and what your priorities are. It comes back to are you trying to optimize for doing things or for getting things done?

Here are some more interesting quotes from the book. There’s a lot to think about there.