I’ve been reading “Managing the Design Factory” by Donald Reinertsen. There is an interesting observation he makes. In manufacturing, you know all of your requirements up front. Whereas, when you are doing design, you know very little up front with most of the requirements being known about a third of the way through. Don’t get hung up on exactly when you know – as long as you agree that in designing a product, you don’t know it all up front. I believe this is intuitively clear.However, while reading this, it struck me, people questioning Lean often point out that we are not in manufacturing – the roots of Lean-Thinking. Yet, it is in manufacturing where we know all of the requirements up front. The irony is that in the Waterfall process you hypothesize that this is possible. In other words, the Waterfall itself is somewhat trying to emulate a manufacturing situation. Lean Software actually suggests that requirements won’t be known until well into the development cycle and that we have to defer commitment knowing things will change.Just thought this was interesting.
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Agree
As an ex-Certified Project Management Professional, I find waterfall is an excellent fit for big projects that are largely static, well known, and often repeated processes. It is perfect for building a house or a bridge.
But software development is all about blazing a trail and creating something that never existed before. There are no roads to follow or plans to repeat. You could just as easily predict how long Michelangelo's next project will be after the Sistine Chapel. Sure the materials will be the same: paint, walls, and maybe even a church. But these are not particularly central to the requirements, nor do they particularly drive the project's duration.
Peter Edstrom