The aim of a project is to achieve a targeted result for an organization, a team, or any organization. In order to deliver this outcome with acceptable quality, project management provides the guidance, control, and best practices to ensure that projects start, progress, and end on a successful path. 

However, in the real world, this path is filled with roadblocks, challenges, risks, and limitations. There are boundaries to a project, which includes the iron triangle, also known as the triple constraint or project management triangle.

Triple Constraint Concept

A project has certain basic characteristics. It is an action that produces something original with start and end dates clearly defined. Moreover, it operates within certain boundaries and constraints, which are mainly the scope, time, and cost of the project. 

Every project is bound by these three interdependent constraints, and any change to one affects the other two, along with the quality of the project and final product. 

Project Management Triangle

A project management triangle effectively represents the three constraints of the triple constraint model, where each side or point represents a particular limitation.


Scope is defined as the extent of the work. It determines what is included, its purpose, objective, boundaries, and the work necessary to produce the final result, whether it is a product, service, or result. 

By extending the scope of a project when scope creep occurs, you disfigure the perfect triangle, and thus the project ends differently from what was originally intended. As a result, if there are no adjustments, the project may miss its deadlines, go over budget because of an extended schedule, or both.


The time constraint is the schedule that the project stakeholders have decided on after the project begins. It is an estimate of the time it will take the project team to finish all tasks and produce the final deliverable. 

A schedule extends beyond the set deadline when there are unexpected delays during project execution, such as additional scope or insufficient resources. Project teams may have to remove some items from the scope or request additional financing to get the schedule back on track.


The cost is the amount that has to be spent on hiring or using the resources needed to accomplish the task. Although a project’s end goal is to provide value to stakeholders, the project’s cost should never exceed the value expected to be delivered. Doing so is bad for business. 

The project team can only perform a certain number of tasks at a time if the sponsor reduces the budget unreasonably. The deadline will likely be missed by the project team. Or it is also possible that they still meet the deadline while neglecting some of the project requirements or scope, which would adversely affect the final result.

The Project Management Triangle As A Tool

Having an understanding of the triple constraints of project management and how they affect project delivery is one thing; using them to your advantage is quite another. To gain value from it, consider using it as a tool to manage stakeholder expectations and know their priorities.

Scope As Priority

When scope is the top priority for the stakeholder and client, additions or changes can be requested at any time, so they can get the particular feature or result they need. It is important that a project manager let the client know a flexible schedule will be necessary to accommodate their requests if the scope is a priority.

Extending the scope will require more time and resources, hence, increasing the project cost. On the team’s part, the project manager should make it clear that taking scope as a priority, they can be prepared for additional work as the project moves forward.

Time As Priority

If the schedule is the most important factor, the project must end by a certain date regardless of what happens. In this situation, the project manager should explain to the client and sponsor that meeting the deadline could cause an additional cost for extra resources or a reduction in scope.

Changing the scope of the project can also affect the end quality of the final product. Therefore, the project manager must also monitor metrics, test work items, along with tracking time.

Cost As Priority

When cost is the most important factor, the project team must work strictly within its given budget. A project manager has to communicate with clients and sponsors regularly and persuade them that working with limited resources may require adjusting schedules, reducing scope, and agreeing to a reduced quality of the final product. 


With the evolution of project management, some experts see limitations in the iron triangle. The concept has been revised by some as a management constraint triangle involving financials, stakeholders, and resources as well. 

PMBOK suggests three additional constraints in addition to the triangle constraints: quality, benefit, and risk. No matter how many project constraints there are, project managers must have all the tools they need, such as project management software. 

It is also important that clients and other stakeholders understand that any change in one constraint will likely affect the others. Therefore, the project manager needs to make sure that everyone understands the trade-offs involved.

Would you like to know what questions a project manager should ask before starting a project? Read our blog to find out.