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Triple Constraint — Friend or Foe?

By Denise DeCarlo, PMP

Many people have heard of the triple constraint, but do you really leverage it? The triple constraint is defined as Scope, Time and Resources, each representing the sides of a triangle, as shown in Diagram A (below). Scope refers to the necessary work to be performed in order to produce the desired project results. Time, of course, is defined as the duration of time it will take to complete the defined scope of the project. Resources include the money and effort expended on people (labor), services and products (for example, the purchase of hardware, building materials, software, manufacturing components, etc.). Leveraging the triple constraint by determining a distinct priority of the components, and managing the project to that prioritization, can enhance the chances for project success.

Prioritizing the Triple Constraint

At the beginning of the project, ask your project sponsor to prioritize the triple constraint components. Frequently, he or she will say, "They are ALL important." They are, indeed, all important, but they should not be treated equally! Undoubtedly one of the elements of the triple constraint is more important than the others. For example, is the end date non-moveable due to other business commitments, regulatory considerations or mandatory stipulations? Or, is the budget fixed and your project absolutely cannot exceed the approved budget level? Or, is scope critical because you are attempting to obtain a competitive edge and your company wants to be the first in the marketplace with a given product? Find out from your sponsor which element of the triple constraint is most important and why, which is second most important and, finally, which is least important.

As the project manager, you will make decisions every day based on the priorities of the triple constraint. If your sponsor has indicated to you that the end date is the first priority, followed by resources and then scope, you will do anything possible to complete the project on time by first reducing scope, since it is the lowest priority of the three, and then by incurring additional resources to ultimately meet the desired end date.

This may seem basic or obvious, but all too often we don't have this conversation with the sponsor and the project manager either assumes a priority of the triple constraint based on perceptions of the situation, which might be wrong, or, worse yet, the project manager attempts to treat all three triple constraint components as being equal and fails miserably because it is impossible to do so. Diagram A shows the triple constraint as a triangle, but it usually is not an equilateral triangle. Changing one of the three constraints almost always has an impact on the other two constraints.

A Common Scenario

Let's assume you did have a conversation with your sponsor at the beginning of the project and she prioritized the constraints as: time, resources, then scope. It's now two months later and the project schedule is slipping because critical path activities are taking longer to complete than anticipated. You have submitted a significant change request to add resources, a 10% overall increase, for example, to the project to ensure the project end date can be obtained. However, your sponsor rejects the change request, stating that the project cannot exceed the currently allocated project budget due to recent budget cuts.

At this point, you must discuss with your sponsor changing the priority of the triple constraint components. It's apparent that resources (money) are now the highest priority, and it is impossible to meet the end date with the current allocation of resources and scope. Because scope was the lowest prioritized constraint as agreed upon, you have already reduced it to the minimum acceptable level by the business, so your next logical option is to move out the project end date. If your sponsor says "that's impossible," then you should remind her that you must balance between the three constraints and something must give. It is essential for you to take a stand and remind your sponsor about the critical balance between the constraints and work with her to stabilize the project.

Educating Your Sponsor on the Triple Constraint

Conversations like this are difficult, but they are essential for the ultimate success of the project. Maybe the business areas can reduce scope some more. Is there any chance some of the budget for the project can be increased? Maybe you can get more internal resources and remove some of the project consultants that are more expensive. It's time to get creative -- but it's not appropriate to compromise the concept behind the triple constraint. If you don't push back, your sponsor will assume you can "pull it off." It is not in the best interest of the project team or the company to have people work even more overtime than they already are and/or reduce the quality of the agreed-upon scope, which is typically what happens.

The prioritization of the triple constraint can, and will, change throughout the life of the project. However, the prioritization should not change frequently and you definitely don't want it changing back and forth. When the priority does change or appears to be changing based on the behavior you're observing from your sponsor, it should be confirmed via an overt conversation with your sponsor. This will enable you to move forward and continue making daily decisions about your project based on the new prioritization of the triple constraint.

As the project manager, it's your job to educate your sponsor and other key stakeholders regarding the triple constraint concept and to manage them effectively. Anyone can understand the triple constraint concept; however, managing the triple constraint successfully is the hard part. It's similar to a diet — the concept of a diet is easy: If you consume fewer calories than you burn, you will lose weight. Easy concept but extremely difficult to implement successfully!

Ensuring All Stakeholders Agree on Prioritization

Another common challenge surrounding the triple constraint is the different priorities that several key stakeholders typically have. Let's face it; our sponsor is not our only major stakeholder. We have key stakeholders, both internal and external, from each of the business entities that are impacted by the project and frequently the stakeholder representatives have different needs (scope) and different priorities. It's your job as the project manager to communicate to all stakeholders the pre-determined priority of the triple constraint components per the sponsor's desire. If this priority is in conflict with the desires of other stakeholders, you'll need to manage those expectations accordingly. Ultimately, the sponsor is typically the person paying for the project, and therefore, should dictate the priority of the triple constraint components.

Where Does Quality Fit In?

Another area of debate surrounding the triple constraint is quality. Where does quality reside relative to the triple constraint? PMI® recommends that you include quality on the scope side of the triple constraint diagram. This is based on the fact that quality activities, such as testing, using standards and templates, and quality reviews, are activities that must be performed in order to deliver the appropriate solution to the customer.

Therefore, if you get pressured by your sponsor and other major stakeholders to reduce testing in an attempt to meet a deadline and keep down costs, you should reduce scope in order to decrease the amount of time necessary for testing. The fewer features (scope) there are, the quicker you will be able to complete testing. However, testing should not be arbitrarily reduced to meet a desired end date. This reduces the quality and stability of the end solution and could permanently tarnish the successful implementation of the end product. If you are forced to reduce testing time and are not allowed to reduce scope, you should request additional resources, via a change request form, to be leveraged during the post-implementation phase in order to deal with the additional problems anticipated once the solution is implemented. This approach can work for IT-related projects, but is not very effective for construction and engineering projects where a minimum level of quality is mandatory to adhere to safety standards.

Everything gets back to the triple constraint. You can leverage the triple constraint concept in almost every situation, including project management conflicts and challenges. We do have options, but our options are based on leveraging the triple constraint, not compromising it. Understanding the power behind the triple constraint concept will make you a more successful and respected project manager.

Denise DeCarlo is a President of Mindavation, a company providing project management training and IT consulting, leadership workshops and team building programs worldwide. Denise is also a senior instructor with ESI. Denise can be contacted via the Web at www.mindavation.com or by calling 866-888-MIND (6463).

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