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What is the project management triangle?

Zoe Averbuch 8 min read
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Project management as a subject area has many different key concepts and terms that are worth getting familiar with. One of them, the project management triangle — also know as project triangle, triple constraint, and the iron triangle — is not without exception.

In this article, we’ll tell you everything there is to know about the project management triangle concept and how apply it your own processes. We’ll also show you a few templates that make it easy to start right away.

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What is the project management triangle?

The project management triangle is a way to visualize the three competing demands on a project manager: time, project cost, and scope.

Using this project triangle, a project manager can understand trade-offs between the three project constraints they’re acting under.

one view of the project management triangle

(Image source)

To understand the iron triangle, imagine an object sitting dead in the center. You can’t move it toward one point without moving it away from the other two.

How does the project management triangle work?

The project management triangle forces you to consider the impact of prioritizing one constraint over another.

If you prioritize time, you’ll tend to get the project done fast. However, either the scope can’t be nearly as large or you’ll have to shell out more money to try to accomplish your work in less time. If project cost is your top priority, you’ll probably finish under your project budget. But you could end up having to hack scope or miss your desired deadlines, since you’ll either be employing fewer or cheaper people (or both).

On the other hand,  if you focus on scope, you’ll likely ship a high-quality, feature-rich product — though you might risk delaying release and going over budget in order to incorporate all the bells and whistles.

The project management triangle is a model used for making predictions. Its usefulness varies directly with the amount of information you have.

Understanding the time corner of the triangle starts with knowing your clients. They will almost certainly not be OK with an expected delivery timeline of “whenever we get around to it.”

While most clients will be at least a little flexible, time is most often the hard point around which your other decisions must revolve — especially if they’re used to a traditional project methodology.

Money is an unusual corner of the triangle, since spending more doesn’t always guarantee better results. For example, you can hire more staff to try to get a project finished faster, but an overstaffed project team can actually harm efficiency and quality if not managed with extreme care.

Project budget is a decision that revolves around how much the client is paying you and how much profit you’re targeting. You need to determine how much you can spend and whether you or the client will tolerate going over-budget.

Scope needs to be tightly controlled in light of the other two project constraints. It’s the one a project manager often has the most leverage over. While it might go against your principles to ship a product that’s less than perfect, the project triangle illustrates why it’s sometimes necessary. The alternative is scope creep: a project that keeps growing forever, yet never feels finished.

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Are there other constraints in a project?

Some project management consultants extend the triple constraint triangle to include thee more constraints:

  • Quality: Similar to scope but not identical, quality reflects the degree to which something is done well while scope is how much is done.
  • Benefits: Using benefits as a constraint recognizes that the developers and customers don’t always have the same standards for what constitutes a successful project.
  • Risk: This describes both anticipating risks and being willing to take risks in the project management process and weighing them against the other constraints. has a Risk Register Template to help you track and manage all your project risks.

free program risk register template from

What is the Agile triangle?

The Agile triangle updates the traditional project triangle to incorporate Agile project management philosophies. If you’re not familiar with Agile, here’s a quick refresher — it’s a modern project management philosophy that focuses on short release cycles, fast decision-making, and tight communication.

An Agile adjustment to the iron triangle

(Image source)

Agile thought leader Jim Highsmith suggests 3 different points for the project management triangle: value, quality, and constraint.

Value refers to the benefit the project provides for the customer, and in some interpretations, to the development team as well.

Quality means the inherent positive traits that make the product awesome: its features, solutions, innovations, etc. Recall from our steak example that intrinsic quality does not necessarily equal value for the customer.

Constraint lumps together all three constraints from the old-school triple constraint iron triangle — the limits in terms of project cost, project schedule, and project scope.

Highsmith’s point with the Agile triangle is that a project manager should not plan out the entire project with an eye toward what’s constraining it. Focus on what’s possible before you plan around what’s realistic.

This Scrum Planning Template can help you plan your next Agile project while keeping the 3 constraints top of mind.

free Scrum planning template from

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How do you manage project plans with the project management triangle?

Answering this question will help you move from the abstract modeling of the project management triangle to the concrete reality of a project plan:

  • Write a scope statement
  • Create a schedule
  • Define the budget

The first thing you’ll need is a project scope statement. This defines your goal in as much detail as possible.

  • BAD: “I want to build the world’s greatest gingerbread house.”
  • BETTER: “I want to build a gingerbread house that incorporates icing and gumdrops.”
  • BEST: “I will build a two-story gingerbread house that incorporates edible decorations such as icing and gumdrops, but no inedible decorations such as Legos or string.”

See the difference? The best project scope statement defines not only what is part of the project, but also what isn’t. It also includes a success factor: when the house reaches two stories and includes edible decorations, the project can be considered complete.

Next, you’ll need to manage the time constraint with a clear schedule. Say your holiday party is in two weeks, so you need to have the gingerbread house finished by then. That’s a hard deadline — you can’t move it, so you’ll have to work around it. It means you’ll have to lower your scope a bit if you realize you can’t realistically build that fancy of a house in that amount of time. .

Finally, lay out a clear budget. You’ll need a certain amount of money for supplies, and a bit extra left over for incidental expenses and unexpected costs (like gumdrops you dropped on the floor). Since your time is a bit constrained, you may decide to bring on a contract employee (your neighbor’s daughter) to finish icing the roof. That increases the budget, but makes the timeframe manageable.

Get started with this Project Plan Template

Choose for project management

Even a seasoned project manager can feel overwhelmed by the number of decisions they need to make each day. Visuals like the project management triangle model are useful because they give your thoughts a framework to latch onto.

That’s why we built the project management software around visual templates that are easy to customize. Not only can you find a model that helps you make your project management decisions, you can also customize it as your process evolves.

Frequently asked questions

Why is the project management triangle important?

The project management triangle is important because it creates a visual way for project managers to understand the balance required between the three project constraints — time, cost, and scope.

What are the phases of the project management lifecycle?

  • Initiating
  • Planning
  • Executing
  • Closing

What causes scope creep in project management?

Poor project management is often the cause of scope creep — failure to monitor changes, deadlines, budgets, and more.

Zoe is a New Jersey native gone Telavivian and marketing fanatic. On a typical day, you can find her writing about the latest in tech whilst making her 10th cup of coffee.
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