The project management triangle (also called triple constraints) has been with us from the 1950s.
It pertains the following concepts:
- The quality of the work is constrained by the project scope, schedule and resources.
- The project manager can trade between these 3 constraints.
- However, change in one constraint will necessitate change in the other two.
The classic maxim was: “Good, Fast, Cheap; choose 2”. However, reality is more complex than that and project managers learned the hard way that this choice had its limitations.
Initially, this triangle was associated with a ‘big bang’ approach. The scope was delivered all-in-one. However, as PMs started seeing the risks of a big-bang, they started devising other approaches. One of them was to reduce the scope and do multiple deliveries to avoid a large risk situation.
This approach was less risky and gave the team time to react when there were some scope changes.
A further evolution happened when the triangle itself was changed by inverting it:
Instead of requirements (and scope) being fixed, PMs started fixing a specific time frame (monthly deliveries) with specific, usually dedicated resources.
This was a truly revolutionary approach, because it gave both management and the project team control on:
- Schedule: by delivering more frequently.
- Resources: there was no reason to tie-up resources who were not needed for that specific scope/time.
It is this methodology that has gained wide attraction is being utilized in the majority of companies.
Finally, it should be mentioned that this approach is quite adaptable to IT deliveries, whether they are software development or IT implementation projects.