Like anything else in business, a business plan should be judged good or bad not in a vacuum but in its business context with its specific business objective. Most of the online discussion about business plans is focused on business plans related to seeking investment, and I`m going to make the assumption in this answer that you are asking about those.
People who read your business plan will already know a little bit about your business because they read your executive summary. But this chapter is still hugely important because it`s where you expand on your initial overview, providing more details and answering additional questions that you won`t cover in the executive summary.
Second, your business plan should be a tool you use to run and grow your business. Something you continue to use and refine over time. An excessively long business plan is a huge hassle to revise—you`re almost guaranteed that your plan will be relegated to a desk drawer, never to be seen again.
It`s trendy to say investors don`t read business plans, but what actually happens is they only read business plans of the businesses they are interested in. They reject businesses from intro and pitch, without reading the business plan.
The more you test and review elements of your plan, the better your plan and business will be. This can save you from spending days developing a strategy that just isn`t feasible.
Because your executive summary is such a critical component of your business plan, you`ll want to make sure that it`s as clear and concise as possible. Cover the key highlights of your business, but don`t into too much detail. Ideally, your executive summary will be one to two pages at most, designed to be a quick read that sparks interest and makes your investors feel eager to hear more.