Project brief

What a project brief is

A project brief, known in French as a cahier des charges, is the reference document that describes what a project must deliver before any work begins. It sets out the objectives, the scope of what is in and out, the functional needs (what the solution must do), the technical constraints, the budget and the deadlines. Its purpose is simple but crucial: make sure the client, the team and any provider share the same understanding of what success looks like, so decisions are made on paper rather than discovered halfway through the build.

What it contains

A solid brief usually covers: the context and goals (why the project exists and what it should achieve); the scope, listing clearly what is included and, just as importantly, what is not; the functional requirements, describing the features and use cases; the technical and design constraints such as platform, integrations, brand guidelines or performance targets; the deliverables; and the budget and timeline. Good briefs also state priorities, so trade-offs are conscious rather than accidental.

Functional versus technical brief

Two levels are often distinguished. The functional brief describes needs from the user and business point of view: what must be possible, for whom, and why, without dictating the solution. The technical brief then translates those needs into how they will be built: architecture, technologies, integrations and standards. Starting with the functional level keeps the focus on the problem to solve and leaves room for the best technical answer.

Why it matters

The most expensive mistakes on any project are made in a vague brief. Catching them on paper is far cheaper than discovering them once development is under way. A clear brief lets several providers quote for exactly the same thing, so you can compare offers fairly instead of guessing. It prevents scope creep by defining boundaries up front, and it becomes the shared reference that settles debates later: if it is in the brief, it is in; if not, it is a conscious change. Without one, projects drift, budgets slip and everyone remembers a different promise.

Common mistakes

Frequent errors include writing a brief so vague it commits to nothing, or so rigid it locks in a solution before the problem is understood. Others are forgetting to state what is out of scope, ignoring priorities so everything appears equally essential, and treating the brief as a one-off document rather than a living reference that evolves with justified decisions.

Project briefs at BeBranded

Scoping a project properly is the heart of our consulting work. Before anything is built, we help you define clear specifications, a realistic budget and timeline, and ruthless priorities, so the project launches on track instead of drifting. The brief we produce is yours: you can hand it to any team or use it to compare quotes on equal terms, and if you want us to build it afterwards, we can. A good cahier des charges is a small investment that saves far more later.