Rethinking the Triple Constraint: Five Project Dimensions
The sign at an auto repair shop asked, “What do you want: good, fast, or cheap? Pick two.” It’s humorous, but it’s too simplistic.
Perhaps you’ve seen a sign at an auto repair shop that asked, “What do you want: good, fast, or cheap? Pick two.” While humorous, the sign is also wise: it acknowledges the reality of trade-offs. You generally cannot optimize every desired outcome of a given situation.
The notion of such a “triple constraint” or “iron triangle” appears throughout project management. The problem is that I’ve seen numerous representations of the triangle with various parameters — size, cost, time, or scope — and various assumptions about what’s being held constant. The classic triangle doesn’t show quality explicitly. Does that mean that quality is a non-negotiable expectation or — more likely — that you get whatever quality the team can achieve within the constraints the other parameters impose? In my view, the traditional triple constraint is wrong, although the concept of constraints and trade-offs is certainly valid.
The Five Dimensions
I think in terms of five dimensions we have to manage on a software project (Figure 1, adapted from Creating a Software…
