Before I start a company, I typically write a couple of founding documents. One of them is very outside-in: it's a scenario-based document, describing the high-level challenge that I'm trying to address and the end user scenarios that we are trying to solve. This attempts to explain what we're trying to accomplish to anyone who joins the company orwe might need to get financing from.
Then I create a second, bottom-up document describing the different technologies that will have to be assembled to accomplish that vision.
