Redmine

Each month (for our workflow), we need to see "how much time we spent on a specific category ?"

For this, we filtered issues by target version & category.
In this view, it will be useful to have a column 'spent time' to easily see the amount of time spent by category for each target version.

For each issue, this column will be filled with the filed "spent time" of the issue's detail view (equals of the sum of all spent time line for this issue)