One of the hardest thing we do, in startups and small business, is figuring out when to stick to the plan and when to back up and try something else. There are no magic formulas, no software that can do that for us. It wraps up a combination of guessing the future, projecting different possible scenarios, understanding what’s at stake, and figuring out where assumptions were wrong, where sticking to the plan makes sense, and where it’s going to be like running your head against a brick wall over and over.