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The project triangle: the project manager's tool for balancing time, budget and scope

To be a successful project manager, you must be able to deliver projects that balance time, budget and scope. Using the project triangle, you can keep that balance all the way to project handover.

The project triangle is used to balance time, scope and budget
30 Jun 2022 | 4 min read
Andreas Agerlund Petersen
Journalist, Digital Marketing Manager and business aficionado. Andreas' long reads keep you updated on business optimization, project management, legislation and the PSA concept.

If you're a serious project manager, you've probably experienced that almost all projects face challenges along the way.

Your project team may be delayed, or it may turn out to be more expensive to develop items for final delivery.

Your customer may also want to add more elements to the agreed delivery.

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Whatever the reason for the change, you must always balance the three crucial variables; time, budget and scope, if you want to successfully complete your project. Because you cannot change one of the variables without also affecting the other two.

To keep your balance, you can use the project triangle.

In this article, you can learn all about the project triangle and how to balance the three variables as a project manager.

What is the project triangle?

The Project Triangle is a visualisation tool you can use to visualise the project's balance between time, budget and scope.

More than a tool, it's a visualisation of the inescapable truth of projects - that you can't make a project bigger without making it more expensive or extending the timeframe. And you can't spend more time without making it more expensive.

When you build the project plan and set the framework for the project with the steering committee and the project sponsor in the start-up phase, you can insert the variables; time, budget and scope in the project triangle.

If you have done your preparatory work well and made sure that there is enough time and budget to achieve the scope (in the right quality), you can say that the project is in balance.

At the start of the project, the project triangle is usually in balance if you have aligned time, budget and scope.

Being in balance means that all sides of the triangle are equal in length. The triangle is in balance.

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But if you adjust one of the variables, it quickly becomes clear that the project is no longer in balance. And then you have to react as a project manager if you want the project to succeed.

Especially if you are to succeed with the fourth variable - project quality - which actually also creeps into the project triangle.

We will come back to this. But first, let's get the four variables in place.

What are the 4 variables of the project triangle?

To understand how the project triangle works in practice, you need to understand what we mean when we say scope, time, budget and quality.

Scope

The project scope sets the framework for what is to be delivered and what is not to be delivered. You can call it the project scope.

If the scope is extended, the project timeframe or budget must be increased to maintain the balance.

Alternatively, you may be forced to compromise on quality if you can't get more time or resources.

Time

How long does your project team have to deliver? When thinking about time, it's a good idea to break down the elements of the scope deliverables into time estimates for how long each deliverable will take to execute.

It also helps you to set a realistic timeline and deadline.

If you have to extend the deadline or the number of hours your team has to spend on deliverables, you will also have to find more budget to pay the team.

Or reduce the scope or quality of delivery.

Budget

How many resources do you have available to deliver?

Resources usually mean hours in the consulting industry (and are therefore closely related to the time factor of the project). But the budget also includes everything from equipment, materials, tools or facility rental.

If your sponsor or client cuts the budget along the way, you may have to limit the time - and therefore the scope - to deliver.

Quality

The fourth variable that is directly affected by the other three is quality.

It can be said that if the balance of the project is not maintained during the process, the quality of the delivery will almost inevitably suffer.

How you define quality depends on the specific delivery.

But you can't spend less time, less budget and increase the scope without compromising the quality of the deliverables.

Use quality to get the time and budget to achieve the scope

When negotiating with clients who are very demanding on price, deadline or want unrealistic value for money, it can be beneficial to meticulously document your expectations on quality based on the framework set by your client.

Too often, project managers fail to engage in the discussion of quality within the context of time, budget and scope.

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But in the end, few will compromise too much on quality. And they will have an increased incentive to agree to an increased budget, deadline or a smaller scope if the quality is in order.

An example of a project where the project triangle is used

Your company has sold an IT development project to a customer.

From the start, you, the steering group and the client agree to deliver a system that can handle the client's internal communication among employees. You agree on a price and that it should be delivered within 12 months.

Along the way, the customer's representative talks to the staff and finds out that it would be brilliant to link the existing task management to the solution you are going to develop.

In other words, the customer extends the scope but does not allow for the deadline to be extended, as the company has to merge with a subsidiary by the deadline, and the system has to be up and running before then.

Since the scope and timeframe are fixed, your only option is to include more developers on your project team - thus increasing the project budget.

Alternatively, you can maintain the project triangle without increasing the budget by cutting the quality of the code. But asked directly, the customer is unlikely to accept a solution that crashes or is full of bugs.

Fast, cheap or good - you only get 2 out of 3

Another way to think about the project triangle (if we briefly ignore the quality variable) is the 2-out-of-3 approach.

It is useful in a negotiation where you need to draw the lines clearly to make a choice.

The 2-out-of-3 approach says you can squeeze two out of three qualitative variables - but not all three at once.

With the three qualitative variables, we understand that all customers want to get their projects executed as quickly as possible, as cheaply as possible and as good as possible ("good" is understood as a fusion of scope and quality in this context).

  • You can get a big, high-quality scope delivered fast - but you won't get it cheap
  • You can get a big, high-quality scope delivered cheaply - but you won't get it quickly*
  • You can also get the project quickly and cheaply - but then scope and quality are limited


*Just for industries that have their employees as the primary cost in projects, price and time consumption are closely related. But if the timeframe is extended, you can avoid involving extraordinary resources, such as external subcontractors or resources from other projects. Involving these increases the cost of time spent on the project.

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How to keep the balance through the project with the project triangle

The project triangle is only a model you can use to understand and visualise the interrelationship between scope, time and budget.

Managing projects in practice, where decisions are rarely based on fixed models, is another matter entirely.

However, there are a few strategies you can use to keep the project triangle relevant and balanced throughout the project.

Choose where to be flexible

It's good to know where you're willing to compromise during the project and where there's no room for flexibility.

You can clarify this with project stakeholders early in the process.

Perhaps the timeframe is not the main priority but can be extended if it means the budget does not increase and you can deliver what is scoped.

Maybe you have scoped some nice-to-have deliverables that can be cut if you see that the timeframe or budget increases more than acceptable.

Be at the forefront and plan for risks

If your risk analysis early on reveals that some of the project's phases or deliverables risk breaking the boundaries of either time, project or scope, it's a good idea to plan how you will manage these risks.

If time is slipping on a phase, is adding resources an option?

If you can make agreements in advance that allow you to maintain balance in the project triangle, you're much better off than if you have to restore balance later in the project and have to negotiate an increased budget, more time or a smaller scope as the project progresses.

Communicate often and openly

If you keep the project stakeholders continuously updated on how your project team is performing against the project triangle variables, any adjustments will also be minor and not come as a surprise to the client and steering committee.

This will make it easier to get support for decisions to adjust the framework if needed.

Feel free to use the project triangle as a visual tool to continuously show if the project is progressing or the scope is starting to expand.

It gives you a good idea of how the whole project fits together and why it is necessary to maintain a balance between time, budget, scope and quality.