A realistic dynamic hybrid flexible flowshop shceduling problem

This thesis is based on a real life hybrid flexible flowshop scheduling problem. Hybrid flowshop consists of multiple identical parallel machines in addition to characteristics of standard flowshop problem. Furthermore, with the possibility of skipping stages of jobs in the current manufacturing system is defined as hybrid flexible flowshop. The flexibility and being hybrid features of the system is usually ignored and is rarely discussed in the literature. In the phase of getting results for experimental studies of heuristic methods , the other papers in the literature that handle the hybrid flexible flowshop scheduling problems deal with the problems as much more limited than the real life. Aim of this thesis is to handle hybrid flexible flowshop scheduling problem with real life data. According to literature, hybrid flexible flowshop problem is already complex and studying with real life data increases the level of complexity. Additionally, while the problem is being analyzed, it is aimed to solve the dynamic scheduling problem to meet uncertain demands by digressing the assumption of being deterministic. Minimization of makespan is defined as the objective function. Heuristic methods are improved as a solution that is based on NEH algorithm with taking advantages of dynamic dispatching rules. Experimental studies are performed with open source library that is managed by Java based discrete event simulation. Thus, experimental data is generated and the effectiveness of heuristic algorithm is analyzed. Moreover, advised heuristic algorithms are studied with real life data. Consequently, the developed methods and the current methods, of which superiority were proved in literature, are discussed.