A backronym developed for Lean startups[1], which can be easily adapted and used by any group developing an idea e.g. in a brainstorming session.
B is for the “Business opportunity”. (This can be swapped for “Basic premise” (e.g. for NPOs) or “Business requirement” in an Agile environment)
R is for any “Risks” that are to be managed or mitigated. (Planned for, insured against, avoided etc.)