The design brief is typically the very first step that recognizes a situation that can be addressed by design.
A design brief is a document that describes in broad strokes an unbalanced situation, and proposes a need for a design to improve the balance of the situation. As such, the brief should contain as much information as possible about the situation and how it is unbalanced. Depending on who authors the brief, it may also contain constraints on the expected design arising from the limits that the participating agents (i.e. client, designer, engineers, users, manufacturers, regulators, etc.) have.
One way to develop a design brief is through scoping.
While one might hope that design briefs are developed collaboratively between all the stakeholder agents, it is often the case that the client agent writes the brief in isolation. In such cases, no matter how hard the client might try to capture the points of view of other agents, the brief is rarely accurate in its representation of anyone's needs except those of the client. It is important, then, for the designer to be sensitive to the needs of other agents because the designer is working as much on their behalf as on the behalf of the client.
This is reflected, for example, in the Code of Ethics of Professional Engineers Ontario, which expressly places the “public good” as the first responsibility of an engineer, regardless of who is paying the engineer to do the work.
When agents first approach a designer to design something, the designer cannot be expected to know anything about the specific situation to be addressed. The design brief is the first step in clarifying what is expected of the designer, and also what the designer is able to provide under the circumstances. The brief is intentionally not very specific because the investment of significant resources at this stage may be wasted if the brief is not accepted by the parties involved. As such, the brief represents a “first cut” at defining the unbalanced situation that is clear enough to let all the involved agents decide if it's worth continuing with the project.
The brief also represents the beginnings of a contract between the client(s) and the designer(s). These contracts have many legal implications. As a result, it is important to develop a brief that is accurate, even though it may not be very detailed.
Designers will examine a brief to determine if it is a reasonable undertaking, if it contains any unreasonable constraints or other limitations, etc. Rarely is a design brief accepted on the first draft; designers will often recommend clarifications or changes based on their reflection of the actual needs as they see them.
Once accepted, the design brief becomes the basis for all other explorations of the unbalanced situation that the designers must resolve. Because of the contractual nature of most briefs, designers must exclude any solution that falls outside the scope of the brief - unless they can convince the client that those changes are absolutely necessary. However, since any changes made usually result in significant delays in the development of the design, the benefits to the client of changes may be more than offset by the delays. This makes it even more important to get the design brief right as quickly as possible.
A design brief for this course is the project description assigned by the instructor. Student teams may question the nature of the briefs, but cannot change the briefs without the instructor's permission.
Depending on the specifics of the course, a design brief may be provided to you, or you may have to come up with your own brief. If you have to come up with your own, you should use scoping to develop it.