We would probably need more detail about the workflow and reporting on it to be able to give a good answer.
I would suggest that you start by looking at all the activities that are in the Moodle core. Examples include Assignment, Quiz etc.
Most activity plugins extend the behaviour or function of these core types.
By reviewing the list, you may find a good starting point for what you want to achieve. The, if the core functions are not perfect, you could find a complementary plugin to provide the additional functionality.