The Triple Constraints of Project Management Explained

The Triple Constraints of Project Management Explained

There are many ways to visualize construction projects and their management, the triple constraint of project management is another way to view these projects. Project management instructors use multiple ways of describing project management since everyone learns differently. The triple constraint is another way of describing the challenges that project managers face when working on a project.

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What Are The Triple Constraints of Project Management

Triple constraint of project management is project management jargon. It’s the same as the project management triangle, the project triangle, and the iron triangle. The project management triangle is the three major points that project managers must keep in mind while working on a project. The points are usually scope, time, and budget, or scope, schedule, and cost. They are similar but every three works together in a different enough way that depending on the project stage, or the type of project, managers are liable to face one issue. Project managers must know all three points to have a productive project.

The idea is for a project’s budgets, scope, and schedule to be within proper balance. Balance puts the project equidistant from all points on a triangle. However, this usually isn’t the case. Often times the assumption around projects is that the only way to be able to complete the project is by sticking to two sides of the triangle.

How The Triple Constraint of Project Management Work in Construction

In construction, the triple constraints of project management will fall into either scope, time, budget, or scope schedule and cost. The triangle is a push-pull series that project managers can use to better understand projects. The idea behind the triangle is if a deadline for a specific stage is moved up, then there will be effects on the other two sides to make up for the constraints. So there could be a higher cost because of the decreased timeline. The triple constraints of project management are things that project managers must work within.

Sometimes project managers take it too much to heart believing that you can actually only get two out of three successfully. This isn’t necessarily the case, and with good planning and even project management software, project managers should be able to work well within the triangle. That does mean that sometimes they have to budge on one side of the triangle depending on what else moves. Here are the triangle sides that project managers can look at to better understand potential constraints.

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Scope management can help reduce changes to the scope and an overall better scope. A good scope outlines the entirety of the project. Scope describes what work must be done on a project. Project managers use the scope to determine how many people are needed, and budget. The scope is the plan. And scope management works to ensure that the project goes according to plan. This is how project managers enforce the project scope. And it is also how project managers prevent scope creep. However, when the stakeholders wish to change the scope, scope management provides the appropriate path for that to occur.

Scope management includes a method of changing the scope through change orders. Project managers use change orders to make changes to the scope, budget and timeline. By updating the budget and timeline with the change orders, it ensures that the project will work within the triple constraints of project management.


Schedule is often one of the legs in the triple constraints of project management. Project managers use the scope to set the project schedule. Every project manager wants the project to go according to schedule, but sometimes things happen that make it difficult. The result is a living schedule that moves with the project when need be. If there are hard deadlines, then a project manager might have to move people or equipment from one project to another. Along with scope, project managers manage the schedule to keep the project on time.

Using a Work Breakdown Structure (WBS) is a way to look at the large project and prioritize the individual steps into manageable tasks. Using something like a Gantt chart can help easily visualize the project schedule giving each task a specific point on the timeline. Time management is an essential skill and can help ensure the project stays to schedule.v

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Budget and Cost

Budget is typically the third segment in the triple constraints of project management. Using the scope, a project manager develops the budget. Project managers put together the budget using data in the estimation process as well as personal experience. However, the budget only counts for so much. Of course, a project manager needs it to be able to determine the cost. And they approve purchases and staff based on it. Project managers use the budget, when a project starts, to help manage project costs. Again, when there is a potential cost overrun, a change order is added to the scope to adjust the scope or schedule to accommodate for the cost.

While project managers try to ensure that the budget will cover the fixed costs, the variable costs are where companies can get tripped up. Using estimating and job costing software can be a way to improve overall budget accuracy. However, if there are changes to the scope or schedule, it can be hard to successfully keep the project within the designated budget. And project management tools can be a good way to ensure that the project stays well within the designated budget.

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Why the Triple Constraint is Important

It’s important to know what the triple constraint is because these are the boundaries that every project has to work within in order to be successfully completed. It’s very difficult to make changes to the scope without corresponding changes to schedule and budget. If a project is driven by these metrics, than changes to one of them will change the metrics for all of them.

Most projects have trade-offs and compromises in order to ensure project completion. Using a triple constraint can help project managers visualize the trade-offs to owners and other stakeholders. Being able to see what exactly has to budge in order to make changes can help the stakeholders come to a consensus on the necessity of the change.

Using a project management platform can be a quick and easy way to keep track of the scope, budget, and schedule. Being able to quickly check the current numbers against projected numbers and the estimates will help improve estimates and identify potential issues.

How to Use the Triple Constraint in Construction Project Management

The triple constraint gives you a firm understanding of the variables involved in a construction project and how they can be changed throughout the lifetime of a project. When projects are running over time then the project manager might have to change the scope or the budget.

The triple constraint is the balance act that all project managers have to work within in order to finish projects. The different sides of the triangle can be managed in order to keep everything in order. However, it will take careful management and preparation to do so.

The Four Constraints of Project Management

Not everyone agrees with whether there are only three or four constraints in project management. The traditional model is the triangle model; however, the square model is increasing in popularity. The four constraints of project management are still scope, budget, and schedule; however, it adds quality. So if the budget decreases while schedule decreases then the scope should narrow. But more importantly, the quality often decreases within these projects. Within construction, there are clear metrics to determine the quality of a project. Adding quality to the triple constraints of project management benefits construction projects and overall benefits the project management process.