In addition, we can divide proposals into categories by context:

Solicited. Written in response to a request for proposal (RFP), request for quotation (RFQ) or a bid, usually by someone outside the organization. In this case the client knows there is a problem and/or need and is seeking to solve it.

Unsolicited. Written by someone who sees a problem or a need for a new service and wants to offer a solution. They can be more difficult to write because you have to persuade your readers on two levels (the problem and the solution).

Internal. Written within an organization to persuade management to support an idea or project. Note that an internal proposal may be either solicited or unsolicited.

Sole-source contract. Written to comply with regulations, usually in a standardized format. Readers will want to understand the problem, know what you propose to do to solve it, and how much it will cost. In addition, they will want to know that you can solve it; they will want to know if you're dependable.

Each type has its own demands and constraints, particularly in terms of the degree of persuasion involved. When writing a solicited proposal, for instance, your audience already knows they have a problem; your powers of persuasion will focus almost exclusively on your ability to solve it. In an unsoliticited proposal, in contrast, you may need to work hard up front to first prove the problem exists before you can demonstrate the value of your solution.

Basic Components-->

Sources

Johnson-Sheehan, Richard. Writing Proposals: Rhetoric For Managing Change. New York: Allyn & Bacon, 2001.