Tag Archives: Iron Triangle

The Demise of the Iron Triangle

The iron triangle was invented by Dr Martin Barnes in 1969 to demonstrate the connection between time, cost and output (correct scope at the correct quality) – see The Origins of Modern Project Management. The correlation remains but the concept of the triangle is fading and becoming more complex.

The problem with the triangle is whilst the three interconnections are relevant; the way the elements interact geometrically is not intuitive or correct. Output should react inversely to the other two dimensions. Less output is bad, but less time or cost is potentially good.

As we move into second decade of the 21st century, leaving the ‘noughties’ behind, PMI have dropped the concept of the iron triangle from the PMBOK® Guide and the search is on for more meaningful and unfortunately complex metaphors to define the challenges of satisfying a project’s stakeholders and customers. This is a multi-dimensional problem and there is a real need for a new paradigm similar to the iron triangle but representing the many different facets of success.

As Albert Einstein once said “For every complex question there is a simple and wrong solution.” And whilst the iron triangle was not intrinsically ‘wrong’ in the 70s, 80’s and possibly 90’s it is certainly incomplete in the complex world of the 2010s.

I have seen several attempts to replace the simplicity of the triangle with tetrahedrons and multi dimensional effort charts but they lack clarity of insight. Another quote from Einstein is “If you can’t explain it simply, you don’t understand it well enough.” The question and challenge is how to replace a project management icon as powerful as the ‘iron triangle’ with a more representative symbol.

What will be the new symbol of project management in the ‘teen years for the 21st century? Any ideas are welcome.