If you’re stuck on getting that business plan done before you start-up, that's fine, but remember, plans are never perfect; they are only ever works-in-progress.
Well, yes and no. If you're looking for investors, then you definitely need a well thought out and written business plan. Take the time to do your research and do it right.
However, if you're going into business for yourself, and you're not looking for financial backers, then you really don't need to invest loads of time (and money) building a detailed plan. The odds are you know more than you think you do about the critical factors that will make your business a success; you may not know it or trust yourself enough to realize it.
You need to do your homework, too, but if you can:
In my experience, most entrepreneurs spend way too much time honing and perfecting their business plan to the detriment of their start-up. By the time they're ready to get their business going they've missed out on countless opportunities.
If you’re stuck on getting that business plan done before you start-up, that's fine, but remember, plans are never perfect; they are only ever works in progress. After investing three-to-six months in marketing your products or services and delivering them to customers consider how much more you'll know about the different areas of your business and, consequently, your plans for it.
It’s good to have a business plan; it’s even better to have some business and the insights that comes from your efforts to land some.
Jim Horan’s "The One Page Business Plan" series of books, available on Amazon, are helpful references...one is sure to be right for the type of business you're starting.
Also, check out the business model canvas for an easy one page planning tool.