Many times, when a plumber books a job, it's with the best intentions that he's going to do the work himself. After all, it's his name on the side of the truck. But sometimes, plumbers book more jobs than they can handle and dole out the work to their assistants. While you may think your repair should get first dibs, if the plumber is overbooked, then he'll prioritize his work based on how complicated each job is. That means if you have a minor repair, you may get the assistant for your job instead of the guy you talked to on the phone.