Not having a schedule is OK if it's your PhD and you plan to spend 14 years on the thing, or if you're a programmer working on the next Duke Nukem and we'll ship when we're good and ready. But for almost any kind of real business, you just have to know how long things are going to take, because developing a product costs money.
Joel SpolskyNever put yourself in a position that will put yourself at risk if you make the wrong decision. We spent cash on everything. It's fashionable to make 'bet the company' decisions, but don't do it.
Joel Spolsky