There is often an interesting tension in projects between adding too much (documentation, controls, milestones, etc.) and stripping it back so far that you end up missing something we need later, or worse that blindsides you.
So how to find the balance?
On the one hand we have:
Frustra fit per plura quod potest fieri per pauciora.
(It is futile to do with more things that which can be done with fewer.)
William of Ockham (c. 1287–1347)
This is the famous “Occam’s Razor” that is a base of much of modern scientific theory.
On the other hand…
It can scarcely be denied that the supreme goal of all theory is to make the irreducible basic elements as simple and as few as possible without having to surrender the adequate representation of a single datum of experience.
(Oft misquoted as “Everything should be as simple as possible, but not simpler”)
Albert Einstein “On the Method of Theoretical Physics,” the Herbert Spencer Lecture, Oxford, June 10, 1933
This sums up the dilemma; strip out the excess but not too much, and this is where many ideological battles have been fought over Agile and Waterfall.
In the Red corner for Agile sits Ockham; in the Blue corner for Waterfall sits Einstein.
One thing to keep in mind is that Occam’s razor is not an blind order that the simplest hypotheses is the best and only route, only that it be used to adjudicate between theories that have already passed scrutiny.
So this really boils back down to choosing the best tool and process for the job. If you’re running an established process to deliver a known product then why not go for Waterfall and the certainty it brings up front.
If however you’re going to have changes, or are heading somewhere novel and such certainty is false then maybe the Waterfall is the last thing you want.
Maybe the key here is make this a conscious step in the early project steps, to evaluate the amount, magnitude, impact and probability of disruptive changes and use this to steer the decision on what is best for the project. After all, it’s getting the project successfully delivered that matters most.
For larger projects, such as enterprise-wide applications or deployments, one paper I’ve seen on the whole Agile versus Waterfall choice is by Jason Fair: Agile versus Waterfall: Approach is Right for my ERP Project? (PMI members can get it free for personal use at the PMI MarketPlace; $15 for non-members.)
Well worth a look…