Write your plan using language that your audience will understand. Accommodate your investors, and keep explanations of your product simple and direct, using terms that everyone can understand. You can always use the appendix of your plan to provide the full specs if needed.
All business plans should establish strategy, tactics, milestones, tasks, assumptions, and essential numbers (projected sales, direct costs, expenses, and cash flow). All business plans should develop accountability and tracking.
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.
In the beginning, one may have the urge to delve straight into specific strategies, such as evaluating production methods, studying market segments, and evaluating the competition—but do not do that, at least not yet.
The most common mistake by far is on profits. Startups that grow don`t produce profits. Investors make money on valuation increases, not profits. Real businesses rarely produce more than single-digit profits. Big profit projections are sophomoric. Take all those profits and dump them into marketing expenses and you`ll be better off.
A business plan is more than a document. It`s a guide that helps you outline and achieve your goals. It`s also a management tool that allows you to analyze results, make strategic decisions, and showcase how your business will operate, and grow. In short, if you`re thinking of starting a business or plan to pitch your business to investors, writing a business plan can improve your chances of success.