A Load case set is composed of Load cases (see Load case). This can correspond to Design load cases (see DLC - Design Load Case) but doesn't have to. When running a load case set, all its load cases will be run in parallel.

Load case sets are only relevant in the Batch manager.

The image below gives an example of a batch with two load case sets:

the load case set Operational conditions is composed of 6 load cases. Each load case has a duration of 600 s.
the load case set Parked conditions is compoased of 2 load case. Each load case has a duration of 120 s.

At the bottom of the window, you can see the number of Load case sets in the batch. See also Load case and Time simulation job.