Iron Triangle Vs Triple Constraints

Earlier “Iron Triangle” was used as Time, Cost and Output(scope), but it was dropped from the PMBOK® Guide 4th edition onwards. The basic Scope, Time, and Cost gained Quality, then Risk, and later Resources. It no longer fits neatly into a triangle.  Is the Iron Triangle still relevant?

People will always try to embellish it but the fundamental problem of balancing what you want, when you want it and how much you are prepared to pay for it always remains. The Iron Triangle just puts the same problem in project context. When the triangle is expanded to include all manner of other factors (risk, resources etc) it can lose its impact.  The triangle still works, and a more complex shape isn’t necessarily a better one. Quality, Risk, Resources and any other variable/issue that limits your options with be additional constraints to consider and address; however, the triangle puts the major project objectives in a simple to understand format. Though the latest editions of PMBOK have added extra metrics to the Project Management dashboard, but they are only supplementary to the traditional Triple Constraints. As you are aware, PM professionals have always employed them for ages and they are fundamental to any project at any given time.

Although, there have been many developments to the structure especially with Agile project methodology such as the Agile Triangle or the Agile Architecture Quality Star, but Iron triangle is still valid & relevant currently in every project scenario and will be forever. In Agile we have heard others also talk about the view that the triangle still exists but that it is flattened somewhat due the speed of embracing change and adapting, in IT when you can patch improvements and changes 20 times a day seamlessly to the client and also deliver things like testing to a subset of users it does open a certain level of experimentation and is no longer iron triangle but it is still there.

The “iron triangle” is simply not a “triple constraint.” The initial plan simply identifies a potential cost, schedule, and capability set. If the plan is accepted, that indicates that the proposed set lies within the organization’s actual constraints of maximum cost, maximum delivery schedule, and minimal capability. The challenge is to identify the true single constraint (which may change over the life of the project) and manage to it.

One can deliver a successful product even while missing the planned attributes as long as the project stays within the actual constraints of the organization. Of course the iron triangle metaphor is still valid, but it is also dangerous in that it implies a simplistic solution to a complex problem. We need to encourage practitioners to look beyond this kind of thinking.

Some project managers don’t believe that the Iron Triangle is meant to absolutely define the “parameters” of a project. Thus believe that the “size” of the triangle (project) is elastic. Depending upon how the project progresses, any of the constraints (and their underlying components) are candidates for revision. As confidence in the team and the upgrade process grows, there could be a reduction of the upgrade testing scope. That reduction might mean additional money or resources could be applied elsewhere to potentially accelerate another part of the project. Over the arc of the project, adjustments like this are in constant play.

 

About Aditi Malhotra

Aditi Malhotra is the Content Marketing Manager at Whizlabs. Having a Master in Journalism and Mass Communication, she helps businesses stop playing around with Content Marketing and start seeing tangible ROI. A writer by day and a reader by night, she is a fine blend of both reality and fantasy. Apart from her professional commitments, she is also endearing to publish a book authored by her very soon.

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