Project Management Guide
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What Are Constraints in Project Management?

With any project, there are limitations and risks that need to be addressed to ensure the project’s ultimate success. The three primary constraints that project managers should be familiar with are time, scope, and cost. These are frequently known as the triple constraints or the project management triangle. Each constraint is connected to the other two; so, for example, increasing the scope of the project will likely require more time and money, while speeding up the timeline for the project may cut costs, but also diminish the scope.

The triple constraints of project management

  1. Time constraint: The time constraint refers to the project’s schedule for completion, including the deadlines for each phase of the project, as well as the date for rollout of the final deliverable.
  2. Scope constraint: The scope of a project defines its specific goals, deliverables, features, and functions, in addition to the tasks required to complete the project.
  3. Cost constraint: The cost of the project, often dubbed the project’s budget, comprises all of the financial resources needed to complete the project on time, in its predetermined scope. Keep in mind that cost does not just mean money for materials — it encompasses costs for labor, vendors, quality control, and other factors, as well.

Let's look at each of the three constraints in detail.

Time constraint

When it comes to time constraints, proper scheduling is essential. According to the Project Management Body of Knowledge (PMBOK), the following steps should be taken for effective time management:

  1. Planning: This includes defining the main goal(s) of the project team, how the team intends to achieve the goal(s), and the equipment and/or steps that will be taken to do so.
  2. Scheduling: The project management team must plot out the realistic timeframe to complete each phase of the project.
  3. Monitoring: This step occurs once the project is underway and requires the project team to analyze how the past stages of the project performed, noting trends and impacts on future plans, and communicating these findings to all relevant stakeholders.
  4. Control: In the control step, the team must, upon communicating the results of each phase of the project, move forward accordingly. That means if things are running smoothly, the team must analyze the factors contributing to that positive outcome so that it can be continued and replicated. If there has been a derailment, the team must know how and why the derailment occurred and correct it for future actions.

A Gantt chart can help to visualize the project timeline and whether they are tracking to the proper constraints.

Scope constraint

Defined upfront, the scope of the project should be clearly and regularly communicated to all stakeholders to ensure that “scope creep” — the term used when changes are made to the scope mid-project, without the same levels of control — is avoided. To keep the scope in check, you can:

  • Provide clear documentation of the full project scope at the beginning of the project, including all requirements.
  • Set up a process for managing any changes, so if someone proposes a change, there is a controlled system in place for how that change will be reviewed, approved or rejected, and implemented if applicable.
  • Communicate the scope clearly and frequently with stakeholders.

Cost constraint

A project’s budget includes both fixed and variable costs, including materials, permits, labor, and the financial impact of team members working on the project. A few of the ways to estimate the cost of a project include:

  • Historical data: Looking at what similar projects cost in the recent past
  • Resources: Estimating the rate of cost for goods and labor.
  • Parametric: Comparing historical data with updated, relevant variables
  • Vendor bid: Averaging the total charge of several solid vendor bids

Effective cost control is paramount to the success of the project.

Further reading: