The Project Management Triangle: Scope, Time, and Cost
Project Management

The Project Management Triangle: Scope, Time, and Cost

Dec 2, 2021

Wouldn’t it be great if every project came in on time and under budget? Sure it would – but as every project manager knows, that rarely happens without a little foresight!Most projects are constrained by three factors – time, cost, and scope – which are known as the triple constraints of project management.Project managers (PM) can use the project management triangle (also known as the iron triangle) to get these three factors under control. Not only is it easier to keep track of what's going on by using the iron triangle — it can also come in handy when providing updates to stakeholders during client or board meetings.Let’s take a look at everything you need to know about the project management triangle and how you can use it to improve the outcome of your next big project.

What is the iron triangle?

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Before we go any further, don’t get confused by the terminology! The “iron triangle” and “project management triangle” are just different words for the same thing.They both refer to the same three constraints of project management – project scope, cost, and time – that can make or break a project.According to the Applied Physics Laboratory at Johns Hopkins University, the project management triangle was first introduced by Dr. Martin Barnes in the 1970s and has been part of the Project Management Body of Knowledge ever since.Different PMs may have different ways of representing the project management triangle, but the three variables are always the same.As a PM, it’s your job to balance the three sides of the triangle and be aware of how any trade-offs will impact the overall quality of the project. This calls for expertise in several areas, including project planning, time management, and project delivery.By using the iron triangle, you and your team members can avoid scope creep and present your deliverables on time and on budget.

The three sides of the project management triangle

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The iron triangle helps you and your team visualize the three main constraints of project management. But what are the three sides and how do they all fit together?The main purpose of the project management triangle is to show you how everything is interrelated. Usually, the three constraints are depicted on the corners of the triangle.If you increase or decrease one constraint, it will stretch the sides of the triangle, and you’ll have to increase or decrease another one to bring it back into shape. Quality is depicted in the center of the triangle, since that’s ultimately what’s at stake!Let’s take a look at the three constraints in the iron triangle one by one:

Project scope

The project scope is, essentially, a description of the project: What are the deliverables, and what needs to get done before the project is considered complete? This might include information such as the quality and quantity of the product as well as the number of users the product is designed for.Since the scope of a project may be determined by clients or external stakeholders, it’s not uncommon for it to change over the course of the project.Sometimes, this takes the form of “scope creep,” in which the amount of work required exceeds what was initially outlined in the project planning process. Other times, the scope of the project grows due to new feature requests or change requests.If the cost and timeline aren’t adjusted to account for the new scope, then something has to give! Usually, this means the quality of the project will be impacted.Starting out with a clear template and checking in with stakeholders at milestones along the way can help to ensure project success even in the face of scope creep.

Project cost

The second project constraint in the iron triangle is cost. Every project needs a budget, which should account for everything from equipment to personel.Of course, cost estimates are just that – estimates – so you can expect your actual costs to change over the course of the project.For example, you may have to bring in new team members to get the project finished on time or adapt to new challenges when it comes to scheduling and scope.If money isn’t an issue, then increasing the budget is an easy way to make up for scope creep and bring the project management triangle back into alignment.But if funds are limited, then you may have no choice but to rethink the project schedule or dial back the scope of the project.


Any successful project needs a timeline, since the amount of time you have to complete a project can play a key role in its success or failure. But adjusting your milestones too often can impact the other two parts of the triangle.For example, you might consider investing in new product management tools to improve productivity only to find that this increases your project costs.Your project budget and the size of your project team can help you determine the amount of time you’ll need to complete a project.Or, you can start by dividing the project into phases and determining how many team members or project hours you need from there.Just remember that your team’s workload, efficiency, and resources can all change over the course of the project, so be ready to make adjustments when you need to!

How to use the project management triangle effectively

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The key to using the project management triangle effectively is to have a contingency plan for delays, budget cuts, and other events. If you don’t already know what to do when one of the three constraints becomes an issue, then you’ll waste valuable time and money trying to figure it out.For example, if you know that your project schedule can’t be extended no matter what, you can be prepared to add extra team members as the deadline gets closer.Or, if the limiting factor is your budget, then you can get pre-approval from stakeholders to reduce the project scope or remove time constraints.It’s also important to use a triangle that aligns with your project management technique. Each will have different advantages, so go with what suits your goals and your team best. For instance, the waterfall method focuses on conserving money and resources, while agile project management focuses on saving time.If your team uses an agile or scrum methodology, then you may want to change some elements of the iron triangle to better reflect your priorities.

Use Anchor AI to take notes and save time

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Adding more team members or extending your timeline isn’t always an option, but there are other ways to boost efficiency and keep your project triangle in good shape. Using productivity tools like Anchor AI can help you save time and resources.You can use Anchor AI to take notes during team meetings. We’ll help make sure you’re all on the same page about the project budget and schedule.Not only will this free up participants to focus on what’s being said, but you’ll have a written record of the conversation you can look back on later.Plus, Anchor AI can automatically identify speakers and detect action items so you can easily keep track of follow-up tasks and delegate new responsibilities.Anchor AI isn’t just for project management: You can also use it to take minutes at board meetings, transcribe interviews with prospective hires, and more.Learn more about how it works here, or sign up to try it out!

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