There's a subtle reason that programmers always want to throw away the code and start over. The reason is that they think the old code is a mess. [...] The reason that they think the old code is a mess is because of a cardinal, fundamental law of programming: It's harder to read code than to write it.

Software development takes immense intellectual effort. Even the best programmers can rarely sustain that level of effort for more than a few hours a day. Beyond that, they need to rest their brains a bit, which is why they always seem to be surfing the Internet or playing games when you barge in on them.

So if you want to get things done, you positively have to understand at any given point in time what is the most important thing to get done right now and if you're not doing it, you're not making progress at the fastest possible rate.

Indeed one of the best ways to deflect attacks is to make it look like they're succeeding. It's the software equivalent of playing dead.

Listen to your customers, not your competitors.

A user interface is well-designed when the program behaves exactly how the user thought it would.

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.