Under normal circumstances, design briefs use a standardized format. They begin with the history and profile of the company undertaking the project, along with the company's previous accomplishments, whether related or unrelated to the current project at hand. Following that, the design brief contains a description of the project, including the descriptions of all problems likely to be faced during the project's creation. It should include any individual constrains on the project, the proposed budget, the proposed length of time it will take to complete, and the individual needs of the problem or problems at hand.
Next, the design brief should contain a stated description of the goals of the project. Along with this, it should include a risk-versus-benefit analysis, any sketches incidental to the project, and any proposed solutions to the problems already described. It should also contain a synopsis of the project, along with a conclusion essentially "selling" the business on the proposed project.
A design brief can be compared to a preliminary blueprint for an engineering project. It presents the company financing the project with sufficient information to let it decide whether it wants to go ahead with the project as stated, or if it wants to make budgeting and cost-saving adjustments to the stated goals and parameters of the project. By creating estimates for cost and time, and formulating all foreseeable problems that might occur, it becomes far easier for the company to determine whether the project is even doable. This could be contrasted against a situation where a company goes ahead without first creating a design brief; in such a case, the company will be proceeding blindly, and might only realize that a project is unworkable or otherwise impossible to complete once it has already invested a potentially substantial amount of time and money into it.