Dear,
In your work center capacity tab under Capacity category 002 define No. of indiv. cap.as 2.
You have no need of two work center No of individual capacity it self work for you. Individual capacities in work center we can use for same capacity of machine. Suppose you have 5 labour for that we create one work center and define Individual capacities as 5.
Hope clear to you.
Regards,
R.Brahmankar