Main Content

Lesson 1: Introduction to Project Management

Constraints to Project Success

 

The Triple Constraint

Perhaps you've heard the saying, “Good, fast, cheap: Pick two.” This sentence illustrates the idea of constraints: Choosing certain options limits others.

The triple constraint refers to a set of potentially competing project priorities, the most commonly recognized being scope, cost, and schedule. Simply put and as shown in Figure 1.1, we can think of this as what needs to be done (performance), how much the project is going to be (budget), and when it is going to be completed (time). 

 

Triple Constraint represented by a Venn Diagram of three overlaping circles labelled Budget, Time, and Performance, with Success in the overlapping spot.

Figure 1.1. Triple Constraint
Adapted from Project Management: Achieving Competitive Advantage, by J. Pinto, 2016

This concept is defined in the maxim “good, fast, cheap: pick two.” When managers are making decisions and managing trade-offs in projects, they often have to  sacrifice one aspect of the triple constraint in order to have another aspect. For example, think about a time when you were approaching the date for submission of a term paper to your professor. As you get closer and closer to the deadline, the “nice to have” aspects of your assignment get cut, and you focus on the “need to haves,” or you may not proofread your document as carefully as usual since you are short on time. Sacrificing quality to meet the deadline and minimum requirements is an example of how the triple constraint works.

The Quadruple Constraint

quadruple constraint represented by a venn diagram of four circles labelled budget, client acceptance, time, and performance with the overlapping area labelled success

Figure 1.2. Quadruple Constraint.
Adapted from Project Management: Achieving Competitive Advantage, by J. Pinto, 2016

As project management concepts were formalized, it was realized that the true success of a project couldn't be defined through the triple constraint of cost, scope, and schedule alone. Companies developed products that were readily available to consumers but unsuccessful in the market. Why were they unsuccessful? They didn't satisfy their customers' needs, and therefore customers did not purchase (i.e., accept) the product (Pinto, 2016). Why might customers not accept the results of a project?

  • It doesn’t meet their needs (i.e., provide what they want).
  • It doesn’t meet the standard of quality they desired.

Due to the realization that customer satisfaction is as important as the other three components, the triple constraint evolved into the quadruple constraint. The quadruple constraint adds a fourth criterion, client acceptance, to the model to reflect the importance of evaluating the client's needs in addition to the three traditional success criteria. Managing cost, scope, and schedule will get a project to the finish line, but if the customer does not buy-in (known as client acceptance), is it truly successful?

The article “From Google Glass to iPhone 4, Five Biggest Tech Blunders” describes several products that had issues in the market due to a lack of client acceptance, including the HD-DVD and the Microsoft Zune (Bajaj, 2016). The lack of client acceptance can be attributed to several factors in either case, but the products that gained the market share (Blu-Ray outsold HD-DVD, and sales of Apple’s iPod far outpaced the Zune) did so due to overwhelming customer acceptance.

Can you think of any other products that met the “triple constraint” but were unsuccessful in the market? 

References

Bajaj, K. (2016, September 22). From Google Glass to iPhone 4, five biggest tech blunders. The Economic Times (Online). Retrieved from http://economictimes.indiatimes.com/magazines/panache/from-google-glass-to-iphone-4-five-biggest-tech-blunders/articleshow/54459595.cms

Pinto, J. (2016). Project management: Achieving competitive advantage (pp. 16-17). New York, NY: Pearson.


Top of page