I will reinforce an aspect of motivation (as many of you have said above). The main thing a manager needs is to ensure that their subordinates feel like they have a personal stake in the project’s success. That is the best way to ensure that the workers will give their best effort in order to ensure the project’s success. When working on any project, let’s say building something as simple as a birdhouse. The only way that it’s going to get built is if you really want to build the birdhouse. If you don’t want to make one, or you have no real stake in the outcome, it becomes very easy to forget or ignore the project and give it less than your best. All other factors are less important. A really excited manager who cares isn’t as important as having workers that care just as much, if not more so.