“…For the ED, the most studied tactical planning problem is staff-shift scheduling [1,3,5,23,29,36,39,74,85,92,99,108,118,124,136,144,145,161,188,191,210,211,216,220,250,251]. Shift scheduling deals with the problem of selecting what types of shifts are to be scheduled, and how many and what types of staff are to be allocated to these shifts.…”