Project Management 101: The Triple Constraints of Every Project

When it comes to project management and the concept of triple constraints, it would be wise for you to remember the story of the Great Wall of China. Around 220 B.C., the original project manager got the first wall done in about 20 years. He got it done in time (we assume) but the scope (performance) of the project changed, so they had to add on to what was already done. Over much of the next 2,000 years, and at an estimated cost of tens of thousands of workers who died during construction (and are buried inside the wall), several imperial dynasties (and many, many, many nervous project managers) continued to work on the wall and all of them had to deal with the same things you do in your career.

Along the road to success as a project manager, you’ll encounter a few bumps and detours of your own, just not on the scale those Great Wall project managers dealt with. But what you will have in common with them is that every project you work on has limits on time, cost and performance. These three items are the triple constraints of every project, and they will have a different priority level on each new assignment you tackle. Time might have the highest priority on one job while cost might be more important on another.

Know the time, cost and performance (the triple constraints)

Time refers to your start date, finish date, duration of tasks and other time-sensitive milestones or deadlines that occur during your project; increments of time that you are able to identify specifically in order to complete your project. In this case, time does not refer to a time savings expected as a result of completing your project.

Cost, also known as Budget, refers to how much the project will cost in terms of materials, supplies and cost of the people working on your project. Cost, in this case, does not refer to any cost savings expected as a result of completing your project.

Performance, also referred to as Quality, Quality Standard, Scope, Output or Specification, refers to the characteristics and standards of your deliverable as well as time savings and cost savings expected as a result of your project.

How do you find out the constraints and priority? Ask questions!

Time: How long do you have to complete the project?

Cost: How much money and what resources do you have to spend on the project?

Performance: What results must your project achieve to meet its purpose?

Once you’ve defined your constraints, then you rank them in order of importance. It’s important to note that the project manager doesn’t truly determine the ranking of the constraints; the project originator and the project goal do. However, as project manager, you must establish what the project originator wants as well as the ultimate goal requirements.


Driving constraint: The number one priority, the “driving force” behind the project. If you fail to accomplish the driver, the project is a failure. It doesn’t matter how well you accomplish the other constraints.

Middle constraint: Less important than the driver, but more important than the weak constraint

Weak constraint: Most flexible and/or least important toward achieving your project goal

Can the triple constraints change during a project? Yes, but rarely. If they change often, this means you haven’t properly defined them in the first place and your project will suffer. Taking the time to accurately define and rank your triple constraints builds a strong foundation toward a successful project. And, don’t worry. Your project isn’t protecting a nation against invading hoards like the Great Wall project managers had to worry about. So you’ve got that going for you, at least!

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