I agree with your point that some amount of planning is always useful in the face of uncertainty. It's only when things are certain or utterly routine that no p

I agree with your point that some amount of planning is always useful in the face of uncertainty. It's only when things are certain or utterly routine that no plan is required. "Most start-ups can get away without a written business plan because the founders have everything that would be in a plan in their head." Even when the founders have it in their heads, writing up a one to two page set of key assumptions and objectives can uncover disconnects, and writing them down allows you to solicit input more widely from friends, employees, and advisors. No successful startup is ever just the founders: you are always asking prospects, customers, partners, friends, advisors, employees, and anyone else with relevant knowledge for advice and feedback.