Hours estimate != Duration
Maybe it's just me, but it's happened to me more than once...
Knowing the products we make and having good requirements for a project, I feel I can make a good estimate hours estimate for a project. However, the project manager seems to think that an estimate of 120 hours will mean the job will be done in three weeks. While I, like many, work more than 40 hours a week, the 120 hours is the time I will be billing the project, not including admin time (manditory department meetings) or support time (since we support our own products).
The project manager for the above 120 hour project was flabbergasted that I told him the development for the project would probably wrap up in four months, not in three weeks. (To note: We were going through a department restructure as well as coming up to a busy support season at the time).
