The Iron Triangle of Project Management

If you have studied even the basics of Project Management, you must have definitely heard of the Iron Triangle of Project Management or one of its aliases,

1. The Project Management Triangle
2. The Project Triangle
3. The Triple Constraint

Let’s take a look at how the Iron Triangle of Project Management actually looks like,

It should be noted here that changing any side of this triangle will have an impact on the other sides as well. It is best to accommodate the change with corresponding change to other sides. For example, lets assume keeping the cost constant and increasing the scope of the project, the iron triangle would then look like this,

Did you notice how the schedule increases as well? That means increasing the scope while keeping the cost as it is will lead to an increase in the schedule (time taken) to complete the project. This means you cannot increase the scope while keeping the cost and schedule constant. The correct way of achieving an increase in scope is to assess the change and appropriately increase the cost and schedule. These three constraints are also known as the Competing Constraints

Three conclusive points to note about the Iron Triangle of Project Management are,

1. The quality of work is constrained by the project’s budget, deadlines and scope (features). Here,
   • Budget – the cost available for the project
   • Deadlines – the amount of time available to complete the project
   • Scope (features) – what must be accomplished (or done) to produce the project’s end result
2. The Project Manager has the authority to trade between the project constraints
3. Any change in one project constraint will lead to a change in others to compensate or Quality will suffer

Some example scenarios are below,

• A project can be completed faster by increasing budget or cutting scope
• Increasing scope may require equivalent increases in budget and schedule
• Cutting budget without adjusting schedule or scope will result in quality degrade

All of this may sound simple because the Iron Triangle is an oversimplification. Trading between constraints is not always possible on real life projects. Increasing project budget on a fully resourced project won’t speed things up! Worst, it might even slow the project down. Remember, 9 women cannot deliver a baby in 1 month!

It should also be noted that project success isn’t solely based on a successful delivery anymore. The Iron Triangle doesn’t account for stakeholders management, customer satisfaction and feedback.

Check more articles on Project Management Basics