“…In the past, manufacturers were more interested in functional area optimization, particularly emphasizing production efficiency and cost performance. Measures of production efficiency and cost developed in the literature include multi-period production planning (Chung and Krajewski, 1984;Leong et al, 1989), capacity utilization (Pinto et al, 1983), optimal staff solutions (Bechtold et al, 1991) and inventory management (Wagner and Whitin, 1958;Wight, 1984;Atkin and Iyogun, 1988), etc. An optimal solution is usually reached without considering continuous operating conditions, schedule flexibility, and employee preferences and availability.…”