The Mythical Triple Constraints

By Bob McGannon on November 11, 2014

The triple constraints familiar to project managers – time, cost and scope – form the basis of much of the literature that discusses project management. Also called the iron triangle which includes quality in the middle of an equilateral triangle, this forms the heart of what a project leader is expected to manage when delivering a project.

The problem is, in practice, most organisations do not behave this way. Delays in decision making, changing priorities and chronic lack of attention can change the dynamic of how the triple constraints are juggled.

The fact is, most organisations have their own profiles for how the iron triangle is managed. There is typically a priority to the triple constraints and the project manager is wise to interview stakeholders to understand their management preferences.

There are some very straightforward triple constraint priorities. For example, quality is paramount if you are building a new medical device; if you are delivering a product in a regulatory environment that has an explicit deadline, time is most important. In most environments however, the triple constraint priority is not so clear cut. Management behaviour and organisational pressures will change the dynamic of your project and the priority of the triple constraints.

So, we need to remember our training in project management – but not hold on to it too tightly! The intelligently disobedient project leader will understand it is not like we read in PMBoK or the textbooks. There is a priority to the triple constraints – the sides of one or more of the triangle are pliable. Bend the wrong one however and you can get yourself in trouble quickly. By the same token, try to rigidly push all of the triple constraints too strongly as inflexible, and you can find yourself in the same doghouse!

Understand the REAL priority of the triple constraints…and you will be more successful, and less stressed, and that is something we all could use – less stress!

Here is the approach I take to understand the priority of the triple constraints:

Ask your sponsor which of the three sides of the triple constraint triangle is:

  1. the driver for the project; then confirm –
  2. the second one that needs to be optimised; and finally validate –
  3. the third side of the triangle that will change when the others are manipulated. The changes here will need to be accepted OR if it changes too drastically, should cause a re-evaluation of the integrity of the project

Doing this at the start and regularly throughout the project and validating this information with the key stakeholders, will avert the dreaded wrath of the sponsor not getting what they had hoped for from your project.

Bob McGannon

Director at Intelligent Disobedience Leadership

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