Why Time Constraint is the Most Important Project Management Constraint

Hour Glass

Frederick P. Brooks Jr., in his famous book, The Mythical Man-Month, wrote, “Adding human resources to a late software project makes it later.” His statement is popularly known as Brooks’ law.

Even before the book was published, project managers and other project stakeholders knew that project duration cannot always be shortened by adding more resources. However, customers and sponsors have always pushed project management teams to reduce timelines.

In my previous article, I raised the question of whether or not duration estimation can be done without making any assumptions. In that article, also, I briefly mentioned that project time duration is probably the topmost concern of most project stakeholders.

You might be wondering why project stakeholders give so much importance to the project time duration. Aren’t there other project management factors that influence a project?

Let’s discuss the importance of time and other factors in project management.

Project Management Constraints

A project constraint is defined as a factor that limits the options of the project management team.

Historically, project management literature recognized only three constraints: scope, time, and cost. These three were called the triple constraint of project management.

The three constraints were deemed to be the three edges of a triangle that were firmly intertwined with each other. It was thought that changing one constraint would change at least one of the other two. This triangle is referred to as the project management triangle or iron triangle.

Project Management Triangle

Later, Quality was added as a fourth constraint that resided inside the triangle.

Time Constraint Triangle

Today, modern project management literature recognizes six project management constrains. These are scope, time, cost, quality, risk, and resources.

Time Constraint Cycle

It should be noted that a project could have many other constraints (political, geographical, and environmental constraints) apart from the six project management constraints.

Importance of Project Management Constraints

Project management constraints define the competing demands of a project. Different stakeholders have different needs. All the constraints are important and should be balanced for making a project management plan.

Let’s take a look at a few examples.

  1. Consider a major sporting event like the Olympics. Such a mega event starts with an opening ceremony at a scheduled date and time. Do you think it is possible to delay the opening ceremony by a day or even an hour? No, with thousands of people in the stadium and millions of people glued to their TVs, the opening ceremony of such an event cannot be delayed. There is a hard time constraint on the start date and start time of such an event.
  1. A medical equipment company announces that it will launch a new pace maker on a designated date. Just before the launch of the product, the company’s’ engineers realize that there is a small snag in the design that can increase the chances of malfunction by a factor of 0.01%. They believe that they will need another 6 months and additional $10 million to rectify the snag. Should the company delay the launch, given that the chances of malfunctioning are just 0.01% and the potential loss of $10 million? Yes, here we are talking about human lives. If the product is good, the company can recoup the losses, but human lives cannot be compromised. The quality constraint is most important in such type of projects.
  1. A bulk mobile phone manufacturing company announced that it will launch their cheapest mobile phone for only $10. However, a few weeks before the launch, the company’s engineers realized that they will need to use slightly older technology to meet the internal cost objective. They believe that the cost of the end product cannot be increased, and that the sales will not be impacted by using older technology. Should the company move forward with older technology given that it will reduce the quality? Yes, the cost of the end product should be kept as low as possible because the company wants to produce the cheapest mobile phone. The cost constraint is paramount in such type of projects.
  1. A Government department has announced a public welfare scheme that should benefit every citizen. Can the department’s officials decide to leave out even 1% of the citizens to save time or cost? No, 100% of the citizens should be covered even if it means extra time and cost. The scope constraint becomes most important in such types of projects.

The above examples are essentially programs, but they can be considered as projects to understand the importance of different constraints. After considering these examples, you can see that different projects have different objectives. We cannot say across the board that any one constraint is more important than another.

Let’s ask another question thought. Why do project stakeholders treat time constraint as the most important constraint?

Importance of Time Constraint

Most people are involved with commercial projects in highly competitive industries. Usually, these projects are done to generate profit. The objective of such projects is to produce a for-profit service or product that can be commercially marketed. Any delay in producing the end result of such a project can reduce the time to market and lead to reduction of profits.

As the often heard cliché states, “time is money.” You can see why most project stakeholders give more importance to the time constraint than any other constraint.


I think when Frederick P. Brooks Jr. wrote “adding human resources to a late software project makes it later,” he realized that most project stakeholders were giving too much importance to the time constraint. In subsequent years, his statement went on to become a law, which proves and the fact that most project stakeholders tend to focus on time constraint and ignore others.

I believe a good project manager evaluates every recognizable constraint while defining the project management plan. The mantra should be to balance the competing demands of a project.

Have you experienced a hard schedule deadline as a project manager? What is your take on time vs. the other five constraints? How do you treat them in your project?

Can you share some real examples where the other constraints became more important than the time constraint? I would love to hear your comments below.

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Written by Praveen Malik

Praveen Malik, PMP, has two-plus decades of experience as a project management instructor and consultant. He regularly conducts project management workshops in India and abroad and shares his project management thinking in his blog, PM by PM.

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