A comparison of sequencing rules in static and dynamic hybrid flow systems

It is well known that efficient scheduling of jobs is essential for improving the economics of production in manufacturing organizations. As a result, extensive research has been conducted on scheduling, especially in job shop and flow shop settings. In contrast, little research has been done on hybrid flow systems, even though they are found in many industries, including beer processing, glass container production, pertroleum refining, plastic-coated cable production, and fertilizer production. Furthermore, the few studies that have dealt with hybrid systems have been limited by the assumptions made about their operating environments. Therefore, we conducted a study that extends the previous work on hybrid systems in two significant ways: (1) it included financially oriented scheduling rules and a new, related performance measure; and (2) the new rules were compared with the existing ones in a large simulation experiment under both static and dynamic (generally encountered in practice) hybrid flow shop environments. To date such comparisons have been made only under static environments. The results show that the relative performances of the scheduling rules differ as the assumptions regarding the operating environment are changed.