What is the iron triangle?

You now know what major projects are, and some of the risks associated with them. But how do you evaluate the overall performance of a project as it is progressing? First, consider the traditional way to assess projects and major projects.

Traditionally project performance is evaluated using what is known as the 'iron triangle'. The iron triangle prompts you to evaluate a project by taking into account three factors: budget, schedule and scope. It is described as a triangle because these three factors apply constraint on any project, and (particularly during the planning phase) when one changes, the others need to change as a consequence.

Let’s explore what is meant by scope, budget and schedule in more detail.

Scope

The first factor you will consider is the scope of the project. The scope refers to:

It also refers to the quality of the delivery or output - so sometimes, in some texts, quality is used instead of the scope.

Budget

The second factor you will consider is the budget (or cost). This refers to:

Schedule

The third factor refers to the schedule or time you will need to carry out the project. This can be described as:

It is very common to think about project performance by analysing if it is running to budget and on time. However, the iron triangle model does have its limitations and you will examine these later in this course. For this week, you will concentrate on the budget and schedule.

Please refer to the glossary to check any terminology you are unfamiliar with: Glossary of Project Management Terms

Coming up...

In the next section you will explore error and inaccuracy in major projects.