There is no such thing as Waterfall

The brilliant Peter Taylor has coined the Lazy Project Manager. I think I might qualify as a Grumpy Project Manager and here is another grumpy missive. This time about the so-called waterfall vs. agile debate, as there cannot be such a debate. Not because waterfall does not exist, it does, obviously, but because Waterfall is JUST A LIFE-CYCLE whereas Agility comprises much more. Its like comparing a banana to a fruit salad. This applies both to software development and project management. And while this issue is probably older, it can at least be traced back to Royce’s 1970 paper Managing the Development of Large Software Systems, and the waterfall software develop life-cycle he introduced in that paper.

Why do I make this extraordinary claim? Especially when so much is written and said about waterfall software development and waterfall project management. The answer is simple, when you strip out everything that so-called waterfall (methods, frameworks, approaches) has in common with either software development or project management approaches. The ONLY difference left is the life-cycle. To prove this first lets ‘compare’ software development using the diagram below.

I know some of you will challenge my mapping of the two life-cycles content compared to what you might do yourselves. I only ask you to accept it as being a reasonable mapping, not the only truth in this universe. My contention is a simple one, what you do to develop software in each is much the same, but with a different life-cycle. The life-cycle, in the end is the ONLY concrete difference.

Hey wait a minute some might say, what about agile behaviors and roles, surely they are different? Its absolutely true that agility has specific behaviours built in and roles for software development. But I have struggled to find anything viable that defines Waterfall software development in those terms. There is no basis for comparison and the life-cycle still remains the only difference.

Now lets look at project management. Royce defined a software development life-cycle NOT a project management approach. Again I have scoured my reference books and the internet. While there is LOADS of stuff about Waterfall project management from the big consultancies and Forbes magazine to individual blogs. Few mention the practicalities of project management, instead the main things most of them have in common are;

[1] the waterfall life-cycle itself, and,

[2] a software development context.

Given the absence of content for a Waterfall project management method, lets see if we can find anything in generic project management that might make Waterfall different. This image shows typical stuff done within project management. Again, I am sure you can add stuff, but the only additions relevant here have to be waterfall specific.

Here then is my challenge, is there anything else waterfall specific to be added to this apart from the waterfall life-cycle? If the answer is NO, then again the only difference between so-called Waterfall project management and ANY other project management, is the life-cycle.

A final thought

During some 35 years in the profession, I have never known life-cycle to be the determinant of project management. Even the Deming cycle cited by many does not stem from project management. Every project professional I have ever known has adapted life-cycles to the needs of the project and organisation. Which also blows out of the water the idea of so-called traditional project management, which, as my mum used to say, like the good old days…they never were.

Waterfall DOES NOT EXIST……..as anything more than a life-cycle. Get hung up on the life-cycle and you may well miss the bigger picture. 

Adrian Pyne

Adrian is a project professional, author and speaker, who has worked in multiple industries and in both commercial and public sectors during his 30-odd year career.