Project plans and project proposals both lay out a road map for how the project will be run and what the results will be. The two phrases are often used interchangeably, and some organizations are indeed the same document. However, there are some key differences that are important to keep in mind.
Project Plan: a document outlining how a project will be implemented.
Project Proposal: a document used to request funding to implement a project.
Spot the differences? Let’s go through how these details matter in practice.
Audience
One big difference between plan and a proposal is the people who read them. Internal project implementors or officers read project plans. External donors or evaluators read project proposals. As in all writing, it is important to take your audience into consideration in word choice and topics covered. Abbreviations commonly used within your organization may be fine for the plan, but donors will not know what you are talking about. Additionally, donors may not have as clear an understanding of local issues like you do, so make sure to provide adequate project background in the proposal.
Purpose
Project officers need the project plan to inform their actions in implementing the project. Donors need a proposal to make a funding decision. This means that the readers are looking for different pieces of information. Project officers will want to look for technical details like deadlines, deliverables, resources, etc. Evaluators will need some of this information as well, but only to evaluate the cohesiveness of the plan, not to act on it. Evaluators also ask another question which implementors typically do not: why support this project instead of another? For this, proposals also need to provide a broader rationale for their project and why it is so important.
Tone
The tone, which sets the mood or attitude of the writing, in both plans and proposals are often very formal. Plans are typically formal documents with an impersonal tone that focuses on the technical details. Proposals, by contrast, still should be formal but also can experiment with more personal tones. Proposals convince donors to take action. To accomplish this, they can be written as an emotional appeal, a factual argument, an optimistic vision for the future, a dire warning of the current situation, etc.
Message
A good project plan explains how the project will be implemented. A good project proposal explains why the project will be implemented. The difference here is very slight, but this shift in tone and writing style has a big impact on applications. Understanding this difference and implementing it will improve both your plans and proposals.
Also, read this article from Tople that explores the bane of many a project manager’s existences: scope creep.