Assuming you manage a group of professionals, you don't need more than a bug / problem tracking system (since you use TRAC, that would be enough).
What you want to do is assign several tasks to each developer, and let them do it. You do not have to know, someone is idle because they are not cars, and if they have no work, they will ask you.
To find out what the developer has done, you read their time sheet (for how long) and track the problem (for what they did). But then again, if someone doesn’t register anything within 1 or 2 days, don’t panic, they are probably facing a difficult problem, and developers usually don’t register anything until the problem is resolved. (some do not like to write at all, because you need to push a little)
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