Lets say there are predefined tasks for a service . These tasks can be automatically created by adapting the process using boolean . This could either be concurrent tasks or Sequential. This isn't an issue.
You would probably need to look at some very clever process design. You can create 4 different 'add task' in the process and when the Incident has reached a particular status you can add a "are all task at end status" precondition in order to move on.
You can then continue and adding on new tasks in your process after this status.