In the scientific community, a rationale is a necessary justification for any type of research study. It identifies a gap in the current thinking and explains how this project is going to look at the topic from a different angle. Project managers use the phrase in much the same way. A project rationale is the strategic compass for a project, describing what the goal of the project is and why you're bothering with it in the first place.


The project rationale is the justification for a project or action, similar to a business case. If there's no business case for the project, then the organization really should not be going ahead with it.

What is a Project Rationale?

The rationale is a statement of facts explaining the reason behind the project. Why is there a need for this particular project or action? What is the problem you are attempting to solve? What viable solution are you attempting or recommending? Or, to boil it down to the bare essentials: why should the business go ahead with this project?

The purpose behind these rationale questions is to show decision-makers what benefits the business would achieve by green-lighting the project, and what would happen if the business did not go ahead with it. Decision-makers will review the project rationale before any other document, so it must be written in a way that persuades them to commit money and resources to the project.

Who Uses a Project Rationale?

Project rationales come straight from the project manager's playbook. Anytime you hire a project manager to implement a project, then the process will kick off by identifying the drivers behind the project. It sounds obvious, but the project management team must understand what is driving the need for the project to ensure the project has the right focus.

Here are some situations when a project rationale will be essential:

  • When the business needs to secure funding or investment for a project. 
  • When you are planning to allocate resources to a project, for example, building a new staff parking facility.
  • When you've identified a problem or an opportunity you wish to pursue.
  • When you need to illustrate the significance of an idea.

What are Some Sample Rationale Statements?

All sorts of things can serve as the rationale behind a project, but typically they fall into one of six categories, commonly known by acronym PESTLE:

Political: The project is necessary due to a change in the regulatory environment at the federal, state or industry level.

Economic: The project is necessary for economic reasons both within and outside the business, such as increased competition, investor demands or the desire for growth.

Socio-Cultural: Changing customer demographics, societal expectations, diversity requirements or similar factors justify the need for the project.

Technological: Advancements in technology are presenting an opportunity to the business and/or the business is being left behind due to its low adaptation of important technologies.

Legal: The project is necessary to keep up to date with the law or meet obligations under health laws, equal opportunity laws and so on.

Environmental: The push toward greener production techniques and sustainable business practices (recycling, sustainable sourcing, reducing consumption, fair trade practices) provide justification for the project.

Internal or micro factors can also provide the rationale for a project. These include management priorities, improving processes, cutting costs, achieving strategic business goals and responding to feedback from staff.

How to Write a Project Rationale

The rationale may be an introductory narrative to a longer business document or it may be a document in its own right. Either way, it will be one of the first documents a project manager writes in order to establish the business case for the project so it must be persuasive. There are no right or wrong ways to structure a project rationale, but you must explain the reason for the project and what the benefits will be.

Ideally, your rationale should include all your research on the problem (your PESTLE analysis if appropriate) and identify what is missing from the current business solution. Follow this with the performance measures for the success of the project, by indicating how the project will meet the objectives listed in the rationale.