Each Subprocess must be assigned to either a User or a Team. If you choose a User as Responsible, that User does not have to be the one to execute the process or mark it as Complete.
For example, if Fabian is out sick and Lisa steps in to cover she can still work with the tasks and mark everything as Complete. This is logged in Strivr, showing that Lisa was the one to execute the report.
Using the Export function you can extract this data and see which user marked something as complete during a longer time period.
When changing Responsible from a User to a Team on a Subprocess, in the User Responsible field, choose the Blank option and you will be presented with a new option to set a Team as responsible.