The fact that a bank or lending institution requires a well-executed business plan is a secondary consideration. The primary purpose of the business plan is to guide the owner or manager in successfully operating the business. Preparing the plan forces the writer to consider all aspects of the business and to confront any problems the plan highlights. For example, a monthly compilation of all known costs, over time, will indicate the revenue necessary to support these costs, plus a profit. This leads to the question of whether or not this revenue number is reasonable. If not, it may cast doubt on the viability of the venture itself. The business plan is a vital management tool that enables the manager to anticipate situations before they become problems—or worse yet, emergencies.