PMcrunch

We all know the definition of a project is an undertaking that produces a product by a target date and within an agreed cost.  This triple constraint (product, time and cost) is what the project manager must plan for and track progress against.  But are the three dimensions equal in priority?
 

The answer is no – some projects are cost constrained; some have an immovable end date while others may place a priority on the product quality.  Understanding the priorities on your project (and agreeing with your project sponsor on the priorities) is critical.
 

The Scope Management Priorities matrix (shown below) is a tool you can use to identify and agree upon the relative priorities of the three dimensions of the triple constraint.
 

 

One box from each row and column is checked off to obtain agreement on which dimension is:
 

1. Inflexible – is most critical and must be constrained throughout the project
2. Adaptable – is negotiable but should be optimized
3. Accepting – concessions can be made as part of a trade-off to meet constraints of the inflexible dimension or to optimize the adaptable dimension
    

Let’s look at a couple of examples:
 

A major sporting event (such as the Olympic Games or the Super Bowl) clearly has a fixed date.  If you are the project manager responsible for preparations, the event date is inflexible and must be constrained.  That leaves the resources/cost constraint and the product scope/quality constraint.  Which of these two is more important?  The sporting event will be watched by millions of people, I would suggest that product scope/quality is the next priority – it must be optimized.  Concessions to the resources/cost constraint will have to be made.  This doesn’t mean that cost is no object! What is does mean is when changes occur on the project, cost will be impacted before the other dimensions.  We can secure additional sponsors, enlarge the volunteer base, or pursue other cost options.  The scope management priorities matrix for the sporting event project would look like this:
 

 

Another project example is the space shuttle launch.  Which dimension is the most critical here?  (If you are stuck on this one – put yourself in the crew sitting on the launch pad.)  Product scope/quality is the most critical and must be constrained.  In other words, we will not launch until all systems are go.  Which is the next priority?  Space missions are very expensive and compete for government funding.  Cost must be optimized.  That leaves the schedule; the launch will be postponed until all the clearances have been obtained and risks mitigated.  (NASA learned this lesson the hard way in 1986.)  The scope priorities matrix for the space shuttle launch would look like:
 

 

The triple constraint on these two projects is prioritized differently.  Changes to scope, cost or schedule will be managed differently.
 

Gord Gibben, PMP
Author Electronic Project Office