فهرست مطالب hossein rezaei badr

One of the most critical problems in managing the car manufacturing factories' final assembly line is Car Sequencing Problem (CSP). The optimal permutation of car models is determined in a mixed model assembly line by solving this problem. In real-world cases, the unforeseen occurrence of disturbances like shortage or delay in feeding required parts to the assembly line cause to stir up an initially planned sequence. In this situation, the car resequencing problem is another challenge that should be solved. This study treats the car resequencing problem with an intermediate buffer before the final assembly line to rearrange the given initial sequence. Two objective functions are considered: (1) minimizing the ratio constraint violations (definitive objective of the car sequencing problem), and (2) minimizing work in process that remained in painted body storage (PBS) buffer. For this problem, a mathematical model as MIP is developed. Since this problem is discussed as intensely NP-hard, a new hybrid algorithm is proposed based on NSGAII and VNS to solve the medium and large scales. The numerical experiments are used according to sample problems in CSP Lib. to run the mathematical model and evaluate the developed approach's performance. The computational results show that the proposed method has a good effect on minimizing two objective functions in solving the medium and large-sized problems.

This paper treats the car sequencing problem in final assembly line considering the unexpected occurrence of parts supply disturbance. In this regard, a basic integer linear programming model is developed using GAMS software and based on that, problem solving algorithm according to a reactive approach with considering supply disturbance occurrence is presented. Considering NP-hardness of the problem, a metaheuristic approach based on variable neighborhood search algorithm has been presented. For evaluating the proposed method, sample problems in CSPLib have been used and for simulating the supply disturbance occurrence, test problems in 3 sizes of small, medium and large have been designed. The obtained results show the high performance of proposed algorithm with respect to the best existing solution in all three categories of the problem.