I have never had to write such a report, except when I left a company. I am careful when writing code to write comments to explain anything that I feel might be remotely unclear to me when I come back to change the code in a years time, and that's enough for me. I don't see the point of a schedule. We use issue and bug tracking, and I work through stuff, based on that. If testing occurs, and I get a ton of reports, I work through the easy stuff ASAP then I knuckle down for the 2-3 items remaining. But, I just work longer hours if need be, the fact is that most schedules are somewhat arbitrary, and making sure you do x tasks in y hours only works if you don't care how good a job you do. Each task takes a finite time to do well, and you need to add hours until the number of hours equals the deadline. If that's not possible, then revisit the deadline and make it realistic.
Christian Graus No longer a Microsoft MVP, but still happy to answer your questions.