Conjunctive simulated scheduling

The scheduling of highly complex job shops, such as those found in semiconductor manufacturing, involves multiple types of work centers, large and changing varieties of the products, sequence dependent set up times, reentrant process flow, dynamically changing environment, etc. These complexities make the job shop scheduling problem very strongly nondeterministic polynominally (NP)-hard and intractable to solve by the traditional scheduling approaches. This paper presents the concept and applications of the conjunctive simulated scheduling (CSS) approach, which incorporates the benefits of discrete event simulation in scheduling the shop and avoids the NP-hard formulation of these complex scheduling problems. The differences between CSS and typical simulation studies and its application to online simulation are also presented.