A Relaxed Waterfall

We're familiar with the two development methods: Waterfall and Agile. Waterfall operates in a sequence of large steps: gather requirements, design the system, build the system, test the system, and deploy the system; each step must wait for the prior step to complete before it starts. Agile uses a series of iterations that each involve specifying, implementing and testing a new feature.

Waterfall's advantage is that it promises delivery on a specific date. Agile makes no such promise, but instead promises that you can always ship whatever you have built.

Suppose there was a third method?

How about a modified version of Waterfall: the normal Waterfall but no due date -- no schedule.

This may seem a bit odd, and even nonsensical. After all, the reason people like Waterfall is the big promise of delivery on a specific date. Bear with me.

If we change Waterfall to remove the due date, we can build a very different process. The typical Waterfall project runs a number of phases (analysis, design, coding, etc.) and there is pressure to, once a phase has been completed, to never go back. One cannot go back; the schedule demands that the next phase begin. Going back from coding, say, because you find ambiguities in the requirements, means spending more time in the analysis phase and that will (most likely) delay the coding phase, which will then delay the testing phase, ... and the delays reach all the way to the delivery date.

But if we remove the delivery date, then there is no pressure of missing the delivery date! We can move back from coding to analysis, or from testing to coding, with no risk. What would that give us?

For starters, the process would be more like Agile development. Agile makes no promise about a specific delivery date, and neither does what I call the "Relaxed Waterfall" method.

A second effect is that we can now move backwards in the cycle. If we complete the first phase (Analysis) and start the second phase (Design) and then find errors or inconsistencies, we can move back to the first phase. We are under no pressure to complete the Design phase "on schedule" so we can restart the analysis and get better information.

The same holds for the shift from Design to the third phase (Coding). If we start coding and find ambiguities, we can easily jump back to Design (or even Analysis) to resolve questions and ensure a complete specification.

While Relaxed Waterfall may sound exactly like Agile, it has differences. We can divide the work into different teams, one team handling each phase. You can have a team that specializes in analysis and the documentation of requirements, a second team that specializes in design, a third team for coding, and a fourth team for testing. The advantage is that people can specialize; Agile requires that all team members know how to design, code, test, and deploy a product. For large projects the latter approach may be infeasible.

This is all speculation. I have not tried to manage a project with Relaxed Waterfall techniques. I suspect that my first attempt might fail. (But then, early attempts with traditional Waterfall failed, too. We would need practice.) And there is no proof that a project run with Relaxed Waterfall would yield a better result.

It was merely an interesting musing.

But maybe it could work.