Project Assumptions and Constraints Explained with Real Life Examples

Assumptions and constraints infographic

In our daily lives, we often make assumptions to support our decisions. However, constraints are obstacles on our path that block our plans and progress. If you are preparing for the PMP Certification exam, you have likely thought about project assumptions and constraints examples. Many projects begin with limited accuracy, and only a few start with adequate certainty. While some issues and facts are known at the beginning, most issues and parameters must be estimated during the planning phase. Successful project managers and business analysts consider the effects of assumptions and constraints while managing their projects. In this article, we will review the key PMP concept: Assumptions vs. Constraints, and discuss common project constraints with examples.

Assumptions vs Constraints

Assumptions and constraints are critical aspects of project management that can influence a project’s performance and outcome. Therefore, project managers strive to identify and document these factors in order to manage them as effectively as possible. Understanding the nature of assumptions and constraints, as well as the key differences between them, is critiacl, as effectively managing them can contribute to a project’s success.

For better understanding let’s analyze the following real-life example;

Assume that you plan to go on a holiday and booked a flight. You planned to leave your home at 16:00 and reach the airport by 18:00. This is the assumption that you made for reaching the airport.

However everything does not happen as planned.

The most significant constraint is traffic density. It may prevent you to reach the airport on time. In a similar manner, projects have also assumptions and constraints that may effect the project objectives. Therefore, you need to identify and control these factors to complete your project successfully.

Project Assumptions Explanied

An assumption is something that is believed to be true based on our knowledge, experience, and information provided by our team members. These are anticipated events or issues that are expected to occur during our project life cycle.

Assumption analysis is a part of the risk management process. If it is not made properly analyze, it may affect the project’s health. The project management plans need to change if assumptions are verified wrong.

For example, you have assumed that all the consumables will be available during the welding activities. However, they were not available and you didn’t complete the welding activity.

After these examples for assumptions, let’s discuss constraints.

Examples of Project Assumptions

In project management, it is crucial to make correct assumptions for project success because incorrect ones often lead to failure. Below are the some examples of assumptions that may be necessary for project teams to make:

  • Resource Assumptions: The project will not stop due to the lack of resources.
  • Cost Assumptions: During the course of project, unit prices will not increase more than %10.
  • Technology Assumptions: Existing equipments and software are adequate to achieve the planned performance.
  • Schedule Assumptions: Vendors will deliver materials on time.
  • Organizational and Environmental Assumptions: An economic crisis is not expected throughout the country

Project Constraints Explained

Assumptions and constraints have different meanings. Project constraints are anything that restricts or dictates the actions of the project team such as the limitation of cost, schedule, resources. Projects must be executed within the boundaries restricted by the constraints.

As per the PMBOK Guide, the following are the six constraints that are recognized as determining factors in project management:
• Scope
• Quality
• Schedule
• Budget
• Risk
• Resources

6 Constraints

All of the six constraints influence each other in that anyone getting affected impacts one or more of the rest.

Unlike the assumptions, there are two types of constraints.

1. Business Constraints
2. Technical Constraints

Business Constraints

Business Constraints focus on the available time, money and resources for a project. Common business constraints include resource limitations and budget and time restrictions.

Technical Constraints

Technical constraints focus on architecture and engineering decisions that limit designs. For instance, we’re constructing an abutment, and according to the design, our abutment should be able to withstand a certain amount of pressure. This pressure limit is our technical constraint.

How to Identify Project Assumptions and Constraints?

Identifying project constraints and assumptions is a crucial first step in project management. To do this, you can utilize various techniques and tools such as;

Brainstorming Sessions

Collaborate with your project team, sponsor, client, or stakeholders to generate a comprehensive list of potential constraints and assumptions.

SWOT Analysis

Conduct a SWOT analysis to examine the strengths, weaknesses, opportunities, and threats related to your project. This helps identify internal and external factors that may impact your project.

Document Review

Review existing documents such as contracts, proposals, reports, or policies to identify project requirements, specifications, and standards that need to be adhered to.

Difference Between Assumptions and Constraints in Project Management

It’s crucial for project success to understand the differences between assumptions and constraints. Here are the main distinctions:

  • Certainty: Assumptions are unverified elements that serve as the foundation for planning, while constraints define the known limits of project factors.
  • Flexibility: Assumptions can change during the course of a project and require validation, whereas constraints are mostly fixed factors that delineate business and technical limits.
  • Effect on Project Strategy: Assumptions assist in shaping the project strategy considering unknown factors, while constraints are limiting factors that prevent you from going beyond certain boundaries.


It is important to define, analyze and document project assumptions and constraints so that as the project progresses the project manager is able to verify and validate the accuracy of assumptions and capture lessons learned. Assumptions and Constraints are inputs to many project management processes. Note that Assumptions and Constraints are defined and documented in the project scope statement.

See Also

configuration management and change management

Contingency Plan vs Fallback Plan

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