How can you tell when a project goes off track? What do you do to get it back on track?

"Whenever I'm involved in a project, I always insist that we start by defining the project's scope, which includes our goals. I make sure that this information is freely available and that everyone knows what is expected of them. I also work with the project manager to develop benchmarks for each stage of the project so as it progresses we can see how we're doing. If at a certain stage we don't measure up to where we should be according to the benchmark, at that point I quickly tackle and resolve the issue so we can get right back on track."