This is a questionsthat I am asked by many starting up a business and the simple andemphatic answer is YES. The fact that a bank or investing individualor institution is a secondary consideration.
Primary focus if thebusiness plan.
The primary and mostimportant role of writing the business plan is to guide and directthe business owner or manger in the operation of the business.Preparing and writing the plan focuses the writer consider all thepossibilities and aspects associated with their business. It forcesthe writer to confront and come up with solutions to any problemswhich the plan may highlight. It helps you to think about yourselfand where you have a deficit in a certain skill and allows you tofocus on these and allows you to search for training opportunities oradvisers to fill this gap.
A good video on what type of business plan would suit you, by Tim Berry:
Financial advantages ofdoing a business plan
A monthly comparison ofall known costs over time, will indicate to you the necessary salesyou need to accomplish in order to match these and a make a profit.It allows you to look at this figure and assess whether it is areasonable number, if it's not then it can cast a doubt on thevalidity of the adventure itself. So it is not just a tool forgetting an investment or working capital but it's a tool to give yourbusiness direction and assess the validity of your hypothesises.
The business plan is animportant and working management tool, which allows the manager toanticipate and compensate for situations before they arise andprevent business emergencies. Foresight and planningare a vital part of starting your own business, don't underestimatethem. You can find more information on writing business plans for small business.