A Task is Either Done or Not Done
Another project manager whose blog I read covered a topic recently that really resonated with me. He covered the idea that it's foolish to try and put a percentage complete note beside a task. I totally agree with his assessment. Even though project managers are encouraged to use tools such as Microsoft Project that have little boxes where you can put in percentages, it's really just a silly game to make it look like there's progress being made.
Tasks, according to Robert McIlree, should be considered either done or not done. There is no in between and it's a waste of time to try and determine if something is 20% done or 90%. Part of the problem is that, “the neophytes on your team usually don't have the experience and judgment to make reliable estimates in this fashion.” The other part of the problem that Robert doesn't cover is the over-confident senior-developer that can't seem to accept that things rarely proceed as smoothly as planned. So these senior developers often have an inaccurate assessment of their progress just like the more junior staff.
A better technique is to make sure all activities are broken down in to short duration tasks, say several days of work, and then mark them as either complete or not complete. This list of completed tasks and incomplete tasks can then be used to come up with a percentage figure for overall project completeness. It is, of course, absolutely critical that tasks be granular enough so that there no, “rude surprises.”