Fatal Business Planning Assumptions
Cole Ehmke
Purdue Extension·2025
What is a disaster? The dictionary says it’s “an event resulting in great loss and misfortune.” For business owners, the translation is “an event that affects the ability of a company to survive.” If you are developing plans for a new venture, then you are making assumptions about how your venture will operate because you do not yet have absolutely accurate information. Your assumptions might be about how many customers you will have, what price you’ll pay for your raw materials, how many people you’ll need to hire, and so on. You may even be developing a formal, written business plan to help you think objectively and comprehensively about what you want to do and how you’ll accomplish it. However, even a formal plan will be full of assumptions you make about things you don’t know. When starting a new venture, you can lose significant amounts of time and capital before realizing your assumptions were flawed from the start or by forgetting that assumptions are assumptions, both recipes for disaster. Here are 10 dangerous business assumptions often made by entrepreneurs. Being aware of them will help you avoid some common—and dangerous—mistakes.