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The PMBOK and the Competing Project Constraints
By Thomas Cutting

Following last article about the project management triangle, one of my project management co-conspirators dropped me a note informing me that the triple constraint is officially dead. The new PMBOK Guide 4th edition has killed it.

In lieu of the binding, restricting, tri-legged barer of logic, PMI has opted for “Competing Project Constraints.” The new PMBOK includes Scope, Quality, Schedule, Budget, Resources and Risk as a representative list of the numerous constraints that a Project Manager faces.

Without reading the text directly I can not make a fully informed decision about the wisdom of creating a multisided polygon constraint. For one thing it doesn’t have quite the same ring as a triangle (I’m sure there’s a bad musical percussion joke in there somewhere). However, here are my initial thoughts.

  1. I whole heartedly agree that Project Managers have more to worry about than Scope, Schedule and Budget. I don’t think there was ever any real misunderstanding of that fact.
  2. By removing the Triple Constraint and accompanying triangular image, we loose the visual used to explain the impact of changing one of the legs.
  3. Of the examples given as other constraints, Quality is easily represented by the size of the area encompassed by the leg segments of the triangle. Although not originally part of the image, it fits.
  4. Another, Resources is generally a factor of the cost (or budget) of the project. If money is no object you can get better and more resources. The New York Yankees and Real Madrid sports franchises, with their ability to buy talent, come to mind. Generally speaking, projects run out of time or money before they experience a lack in available resources.
  5. For the other, Risks, I need more explanation for the use of the term “constraint.” If the term means “factors that may adversely impact your project” then I would agree.

Perhaps that is the basis of the change in the terms used. PMI may believe that it is doing us a favor by widening the term to show the myriad of chainsaws and knives we need to keep juggling. My fear is that it opens the door for management to defy the simple logic that if they increase scope, schedule or budget, one or both of the other legs have to adjust.

If we are expanding the number of constraints, maybe we just need a different image:

  • Picket Fence – Each of the slats represents a constraint holding the project level.
  • Suspension Bridge – All of the cables adjusted to keep the path safe for passage.
  • Multi-legged Table – Legs adjusting together to support the project.

Whatever the symbol, I will miss the triangle.

Thomas Cutting, PMP is the owner of Cutting’s Edge ( and is a speaker, writer, trainer and mentor. He offers nearly random Project Management insights from a very diverse background that covers entertainment, retail, insurance, banking, healthcare and automotive verticals. He delivers real world, practical lessons learned with a twist of humor. Thomas has spoken at PMI and PSQT Conferences and is a regular contributor to several Project Management sites. He has a blog at (

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