The Triple Constraints of Project Management: Time, Scope, and Cost

In the course of planning a project, three main factors determine what is possible: time, or how long the project will take; cost, or how much money will be spent on the project; and scope, the deliverable at the end of the project. Increasing or decreasing one will affect the others. To successfully deliver on a project, the project manager must balance these constraints.

What is the triple constraint triangle?

The triple constraint triangle of project management is the visualization of a triangle, with sides formed by time, scope, and cost. These three factors are the constraints that project managers juggle in order to keep a project running as expected. 

Time

Time is how long the project will take. It’s important for project managers to make sure the team finishes the project before a deadline. A project manager must figure out how long a project will take to complete and ensure they have enough people working on the job to complete it in time. 

Scope

The scope of the work refers to the deliverables of the project or the end result of the work. The scope should be clearly defined before beginning work and closely monitored throughout the project. Scope creep, or the project getting bigger or changing without proper protocol, can throw the constraint triangle off balance. 

Cost

The cost is the budget of the project. Clients and project managers agree on a budget prior to beginning the project, and keeping a project on budget will be one measure of success. 

When a project is met with one of the constraints, the project manager uses the triple constraint model to compensate and bring the project back into line. Time, scope, and cost interlink in such a way that if one shifts, the others must as well. Let’s take a closer look at how these three factors relate to one another. 

How time, scope, and cost are linked 

When one of the triple constraints goes off track, the project manager may need to adjust. Here are some common ways that a project manager might adjust to keep the project on track. 

Over budget

When a project goes over budget, it’s on track to spend more money than the client agreed to pay. Budget is the cost constraint, which means that scope or time must shift to accommodate. 

Shifting scope means lowering the expected deliverables and completing less work, which also requires less time to complete and therefore costs less. Another option is to find another way to cut time, such as completing the work with less labor or tools. In that case, the scope would remain the same, and only time and cost would adjust. 

Scope creep

Scope creep happens when the expected deliverables get bigger and bigger as the project goes on without following proper procedures, such as making change requests. When scope expands, a project manager can adjust time and cost to compensate. 

If the scope gets bigger, the project manager can ask for more budget to increase the labor, tools, and material needed to complete the project. With enough additional funding, the project manager might avoid pushing the schedule back. Otherwise, it’s likely a bigger project will require a longer timeline to complete. 

Over schedule

When a project runs over schedule, a project manager might shift cost or scope to get the project done on time. 

By adding money to the project, the project manager could access better tools or pay the labor costs of a bigger workforce to get the project done. Alternatively, they could meet with the client to reduce the scope of the project. 

Examples of the triple constraints of project management

To understand these concepts in the real world, let’s examine some examples of triple constraints and how they affect project management:

Construction deadline

A construction company is building a new office complex for a client. The client requested to move into the building a month earlier than originally scheduled. The project manager might accommodate this request by increasing the budget and bringing in a larger crew to finish the project faster. Or, they might prioritize certain areas of the building to finish early so the client can move in while construction continues, which would be an example of rearranging the scope to fit the new requirements. 

Marketing scope creep

A marketing team is preparing a package of marketing materials for a client ahead of a new product launch. The client requests five additional pages of material. The client doesn’t want to push back the product launch, so the time constraint has to remain the same. The project manager and the client will have to agree to either increase the budget and use more labor hours and resources or they will have to remove other materials to make room for the new additions.

How to manage the triple constraint

Once you understand the importance of the triple constraints on a project, the next step is to learn the best practices for how to manage them. Here are some tips to help you use the triple constraint triangle as a tool for success: 

• Understand non-negotiables: Depending on the project and client, some constraints will be more flexible than others. For example, budget might be negotiable while time and scope are not. By understanding what’s more important to your client, you are more likely to successfully deliver on their expectations. 

• Be aware of other factors: In some products, factors like the quality of the final product will be an important constraint as well. Be flexible to a more adapted model of project constraints for whatever your project needs are. 

• Communicate with stakeholders: Managing projects takes skill, and clear communication at every step of the way helps project managers manage expectations and get the buy-in they need from stakeholders.  

How to get started in project management

The Project Management Institute offers a Project Management Professional (PMP) certification for you as a project manager to demonstrate your skills with globally recognized credentials.

To qualify for the exam, you can either complete your high school diploma and gain 60 months of experience leading projects, or you can complete a four-year degree and gain 36 months of project management experience. In either track, you’ll need to have the experience within the past eight years and gain an additional 35 hours of project management training.

After completing the requirements, you’ll be eligible to take the PMP exam and earn your certification. 

Read more: How to Get a PMP Certification: An Overview

Benefits of becoming a certified project manager

The advantages of getting project management certification include:

• Higher salary: The Project Management Institute reports that certified PMPs made 16 percent more money than their non-certified counterparts [1].

• Community: The project management institute is a global organization with over 600,000 certification holders worldwide, creating opportunities for professional networking and potential mentorship [2]. 

• Confidence: Earning your certification can help you feel confident in your skills and secure in your understanding of industry best practices. 

Get started on Coursera 

On Coursera, you’ll find resources to help you get started in your career as a project manager. Consider Google Project Management: Professional Certificate offered by Google Career Certificates to help you develop your project planning, change management, and risk management skills.

This course is beginner-friendly and takes approximately six months to complete all the courses, although you could also take any of the courses individually.