A business that makes sense and is going to be sustainable in the future is one that has that clear vision within which all the smaller parts contribute to make it successful.
However, business planning is an ongoing process and it should be updated regularly to assist in forward planning, the challenge for the entrepreneur while preparing a business plan is to communicate his ideas and identify gaps in management information about their business, competitors and the market.
It seems to have been put there to fill the need to attribute a certain sum to marketing. Make sure you are researching each point of your budget, make sure that you are giving it context and it makes proper sense within your overall plan.
Describe the manufacturing or operating process and associated costs. Contain believable finical projections, with key data explained and documented.