The Project Book

CHAPTER 42 WATERFALL

What is meant by a waterfall project? The waterfall model entered the corporate lexicon in the 1970s to describe a design approach in software engineering by the TRW Defense and Space Systems Group. It was used to signify the cascading of customer requirements towards implementation (see diagram below).

Bell and Thayer (1976) concluded that ‘problems with requirements are frequent and important. Differences between types of requirement problems is quite small between projects. Improved techniques for developing and stating requirements are needed to deal with these problems’.

Amazingly, these issues still exist today, more than 40 years on.

Essentially, the waterfall approach requires that you gather everything up before you start the project: the needs and priorities of the customer; the design of how it will be built and put together; how it will be tested to make sure (a) it works and (b) the stakeholders are happy; and how it will be maintained once the project is completed.

The best way to think of it is like a big Lego set. You have everything in the box — all the pieces, the instructions, the tools (if required). Then all you have to do is review the design and estimate who you’ll need to be involved, how long you think you’ll need, the quality expectations and how much it will cost. Led by my son, the people required for this project would be him, ...