I've had this problem before, and last time I thought I would try to estimate the time it would take to do the tasks, and realised I had no idea of how much time I take on things. So I got an iPhone app and started tracking my time. The major document in question just got issued for review, and looking back at my time log, it took way longer than I would have ever guessed. There was also a diagram in there that need lots of calculations done, and that diagram took 12.5 hours, and the main document took 50 hours. Now that I have some data I'll estimate better next time, but it's hard when you are doing new things you have no idea of how long they will take. Looking at my log I am suprised at how long things have taken, and not suprised now that I haven't been meeting any of my timelines.