The orthodox measures of project success are, when you really think about it, absurd. They measure inputs not outputs but what you want is outputs.

The Triple Constraint Measures Are an Assault on Your Time and Money

The most common measure of project success is whether it is delivered “on time, on budget and to specification/scope”. These measures are known as both the ‘Iron Triangle’ and the ‘Triple Constraint’.

However, if you are measuring your projects’ success by ‘on time and budget’, you are wasting your time and money.

Using these obsolete measures is expensive and wasteful. However, use of these measures is widespread which is frightening.

In 2013 we surveyed a range of CEOs, CFOs, CIOs, CXOs, Project Managers and Chairmen to ask them their primary measures of project success. To our surprise (and horror) all except the chairmen said, “On time and on budget”. Only the chairmen got it right with, “Improved business performance”.

Taking Your Eye off the Ball

This fixation on ‘on time and on budget’ is severely compromising projects and their results.

Measuring project success by the on time and on budget measures:

  • Misdirects the attention and focus of the management, project and governance teams on to controlling the inputs rather than delivering the outputs. If you’re going to be measured by ‘on time, on budget’ but not on benefits realization, this encourages compromising the delivery of the business outcomes and benefits to come in 'on time and on budget'. These compromises can generate long-term problems in terms or lack of organizational responsiveness and reduced competitiveness that lead to a loss of productivity and profitability.
  • In addition, your can potentially miss opportunities to increase the business value of a project because “it might cause the project to go over budget”. In one organization, a 1% increase in the project cost would deliver twice the production capacity for the future. In another organization a 10% increase in the project cost would deliver a tenfold return. A myopic focus on “coming in on budget” can cause these opportunities to be foregone.

Would you really commission a project to see if “this time we can deliver something on time and on budget”? No, there must be more to it than this.

Some Basics – Why Do You Do Projects?

You commission projects (and programs) to realize the benefits. These ‘benefits’ are not delivering the project on time and on budget, but, say, reducing operating costs, improving productivity, increasing customer retention or launching new advanced products, and so on.

The corollary to ‘you can manage what you can measure’ is that you focus on what you are being measured on. When you are measured in terms of being ‘on time and on budget’ then you can achieve this by, for example:

  1. Increasing the estimates to give yourself adequate ‘wriggle room’—increasing the project’s costs but reducing its (net) value, or
  2. Compromising the outputs to meet these measures—controlling the project’s costs by compromising the delivered value.

The time and cost-to-deliver estimates are inputs to the project. They are the ‘constraints’ within which the project is to be delivered. However, they are NOT the goal of the project. They are a control framework, an input not an output. They do not define the business value sought.

The Absurdity of the Triple Constraint Measures

Measuring by on time and on budget is like measuring a builder’s success by whether or not they exceeded the number of the bricks and concrete they had estimated to be required. Would you say, “Fantastic, no extra bricks required, you’ve done a great job”? I don’t think so.

You’d be looking at the functionality and finish of the house, how it suits your lifestyle needs and delivers the benefits you sought. These dimensions represent ‘success’.

But again, imagine if a builder was being measured in terms of bricks and concrete usage. Then, if you were that builder and you were running out of, say, bricks, you might make some rooms smaller (compromising the result) or leave bigger gaps between bricks (weakening the structure), or make some other compromise to come in ‘on bricks’, as it were.

But, if as the builder you are being measured on the quality of the result and you’re running out of bricks then you would go back to the owner (sponsor) and give them the options:

1. Buy more bricks – a once off increase in costs

2. Reduce the size of some rooms – an ongoing compromise and future operational constraint

3. Reduce the quality of the build – an ongoing compromise and reducer of value.

The owner can now make their choice and control the quality and value of the result delivered.

This challenge to 'on time, on budget' as the core project success measures can be seen as confronting. But we further illustrate how absurd and dangerous continuing with these measures in a free webinar join us!


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Topics: Project Success

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Revision History

First published: Simms, J. (Oct 2015) as "The Absurdity Of The Triple Constraint Measures Of Project Success"

Updated: Chapman, A. (March 2020), Revisions and Corrections