You can only delete work patterns that are not currently in use and that are not historically attached to a current, future, or leaver employee.
If you can't delete a work pattern or can't set it as not in use, you need to check if it's in use within a user's or leaver's record, either currently or historically. To do this, follow the steps below:
Create a query on work patterns and filter on the work pattern you want to delete.
Then, open the query and click Options.
Tick Include leavers and Show history.
Once you have identified which users have this work pattern assigned, based on the above results:
Go to the user's planner and click the work pattern drop-down.
Assign the user to a different work pattern.
Set the effective date to at least 1 day before the effective date of the work pattern you want to delete.
Set the user back to the correct work pattern.
When it has been removed historically from all records, you will be able to delete the work pattern.