I've been tracking my work time in org-mode for several years. My normal practice is to use clocktable mode in the agenda for daily tracking, and a clocktable block in my main projects file for monthly tracking. Both of these give me sums of my work time by file hierarchy, which in my org files corresponds to areas of responsibility and projects.
This is great, but now I need to be able to track time in this way, but also by type of activity (i.e., how much time on project management tasks, how much time on documentation, how much on customer meetings, etc.). I could tag the particular tasks I work on with tags for type of activity, but is there a way to get summed times (daily or monthly) by tag?
Has anyone had to do this (sum times in two different ways)? If so, what did you do?