Triple Constraint in Project Management

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The main aim of Project Management is to deliver a quality project. The quality of any project revolves around the 3 following factors.
1. Scope
2. Time/Schedule
3. Cost/Budget
The Triple Constraint Theory in project management describes these three factors.

triple constraint in project management

What is Triple Constraint Theory?

The constraint can be defined as any limitation or restriction placed on a project. For example, setting a deadline for your project for its completion will be a time constraint for your project.

Thus, Triple Constraint Theory says that every project operates within the boundaries set by the three constraints (i.e scope, budget, and time) of project management. These parameters help to evaluate the success and failure of the project.

Project Management Triangle:

The project management triangle is a model that represents these constraints. It’s also known as the project triangle, the iron triangle, or the threefold constraint.

project management triangle

It contends that:

  1. The scope, budget and timelines of the project all have an impact on the quality of the work.
  2. The project manager can trade between constraints.
  3. These constraints are interdependent; therefore If you want to change one constraint then the other two will also affect.

Let’s see what are these constraints one by one:

 Scope constraint:

Scope of an project

The project scope defines the actions and activities that are carried out throughout the project development process, from beginning to end. Thus, it is the most important part of the project development process.

Dependency: If we increase the scope then the time and budget will also increase. For Example – Adding more features can stretch a project’s time and budget constraints. You’ll either need to extend the deadline or assign more people to the work, increasing project costs.

The PMI lists six processes that are part of scope management:

  1. Plan Scope Management
  2. Collect Requirments
  3. Define Scope
  4. Create Work Breakdown Structure
  5. Validate scope
  6. Control Scope

 Time constraint:

Schudle/time constraint

It is necessary to understand the time limit for delivering the project as per the client’s requirement.
Determining how much time it will take to complete the task helps to build a timeline in each iteration. Based on this timeline setting up the deadline for the project release is very essential for meeting the client’s requirements.

Dependency: A tight time constraint could mean an increased budget and reduced scope.
For Example – If we have a tight deadline for the project then to complete the project on time we require more resources which will also lead to an increase in the budget to provide extra resources.

The PMI lists seven processes that are part of Schedule management:

  1. Plan Schedule Management
  2. Define Activities
  3. Sequence Activities
  4. Estimate Activity Resources
  5. Estimate Activity Duration
  6. Develop Schedule
  7. Control Schedule

Cost constraint:

Budget Constraint

Estimating the cost for the project and setting the overall budget limit helps to frame the over budgeting problems in the projects. Resources used in the projects are the key factor that affects the budget.

Dependency: A tight budget could mean increased time and reduced scope.
For Example – If we reduce the budget of a project then to balance the workflow we either need to reduce the requirement to complete the project on time or we need to extend the deadline if we can’t compromise on requirements.

The PMI lists four processes that are part of cost management:

  1. Plan Cost management
  2. Estimate Costs
  3. Determine Budget
  4. Control Costs


A successful project manager needs to keep a balance between the triple constraints (Scope, Time, and Cost) so that the quality of the project or outcome is not compromised.

Written by 

Gaurav Kumar is an Intern in Knoldus practicing in Agile Studio. He thrives on difficulties and set objectives for himself on a regular basis. He always keeps himself in a learning state because learning and practicing is the only key to success.