Des Traynor shares some insights on how he works with startups in Asking Questions beats Giving Advice:

The first question I ask (though sometimes I just ask myself) is an easy one: is this viable, feasible, and desirable? The answer has to be yes on all three counts—no two are enough. In fact, pick any two, and you’ll think of a start up that failed because they missed the third.

This approach shares parallels to the “problem frame diagram” approach I discuss in Usable yet Useless: Why Every Business Needs Product Discovery. The goal with that approach is to identify the user needs and business goals of the product, as well as the core competencies of the organisation.

Des goes on to describe some of the key things you have to think about before launching a product. If you do Product Management on the web, his post is highly recommended.