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The iron triangle

A key part of the initiation phase of the project life cycle is understanding the triple constraints of time, scope and cost – the iron triangle.

The iron triangle is a project management tool that shows how three factors can be linked. If two of the parameters (ie points on the triangle) change, it affects the third. Within project management, these parameters are typically time, cost and quality. The video above explains this concept.

Once a project manager has committed to a project, the cost, time and quality can seldom be compromised without renegotiating project terms. In every project, a change in one or more of these things will have predictable impact on the others. For example:

Faster time + increased quality = higher cost

Faster time + lower cost = lower quality

Higher quality + lower cost = slower time

Essentially, we can increase two of the three parameters, but it will come at the expense of the third. This is why sometimes the iron triangle is called the triple constraint – these three parameters constrain every project.

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Project Initiation

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