The flexible job shop scheduling problem (FJSP) is considered as an important problem in the modern manufacturing system. It is known to be an NP-hard problem. Most of the algorithms used in solving FJSP problem are categorized as metaheuristic methods. Some of these methods normally consume more CPU time and some other methods are more complicated which make them difficult to code and not easy to reproduce. This paper proposes a modified iterated greedy (IG) algorithm to deal with FJSP problem in order to provide a simpler metaheuristic, which is easier to code and to reproduce than some other much more complex methods. This is done by separating the classical IG into two phases. Each phase is used to solve a sub-problem of the FJSP: sequencing and routing sub-problems. A set of dispatching rules are employed in the proposed algorithm for the sequencing and machine selection in the construction phase of the solution. To evaluate the performance of proposed algorithm, some experiments including some famous FJSP benchmarks have been conducted. By compared with other algorithms, the experimental results show that the presented algorithm is competitive and able to find global optimum for most instances. The simplicity of the proposed IG provides an effective method that is also easy to apply and consumes less CPU time in solving the FJSP problem.

No abstract

No abstract

Abstract-Modern manufacturing systems emphasize the need to improve the overall efficiency of the system and achieve global optimality rather than striving for excellence in isolated individual components. Integration of process planning and scheduling, which were previously treated as spate entities, has become an important area of research for accomplishing this goal. This paper presents a novel optimization algorithm for integrated process planning and scheduling (IPPS) problems. The algorithm is based on sorting the operations into different priorities. The experimental results show that the proposed algorithm can effectively solve IPPS problems.Index Terms-Distributed process planning, Integrated process planning and scheduling, Optimization algorithm, Priority-sort based optimization algorithm.

No abstract