عنوان مقاله :
كمينه‌كردن تعداد كارهاي تأخيردار در زمان‌بندي جريان كارگاهي با كارهاي رو به زوال و ورودي‌هاي غير همزمان
پديد آورندگان :
فخرزاد، محمدباقر دانشگاه يزد - گروه مهندسي صنايع , ندوشن، محمد سليمان دانشگاه يزد - گروه مهندسي صنايع
كليدواژه :
فعاليت‌هاي رو به زوال؛ , جريان كارگاهي , تعداد كارهاي تأخيردار , شاخه و كران , ورود غير همزمان
چكيده فارسي :
در اين مقاله، زمان‌بندي كارهاي رو به زوال با تابع زوال خطي روي جريان كارگاهي دو ماشين با هدف كمينه‌كردن تعداد كارهاي تأخيردار و با فرض ورود غير همزمان كارها بررسي شده است. براي به دست آوردن جوابي نزديك به بهينه در زماني كوتاه، يك روش ابتكاري و براي حل دقيق آن يك الگوريتم شاخه و كران ارائه شده است. نتايج نشان مي‌دهد الگوريتم شاخه و كران مسائل را تا 24 كار در رده مسائل بزرگ و 22 كار در رده مسائل كوچك، در زمان منطقي حل مي‌كند. همچنين درصد بالايي از گره‌ها در روش شاخه و كران توسط اصول غلبه و حدود پايين قطع مي‌شود كه نشان‌دهنده‌ي كارايي الگوريتم شاخه و كران است. متوسط نسبت جواب بهينه به جواب الگوريتم ابتكاري حداكثر برابر 1٫15 است كه اين عدد در مقايسه با ساير تحقيقات مربوط به تعداد كارهاي تأخيردار عدد بسيار خوبي است.
چكيده لاتين :
In this paper, minimizing the number of tardy jobs in two-machine flowshop scheduling with deteriorating jobs and release times is discussed. In most of basic scheduling problems, the processing time of the jobs is assumed to be constant. This assumption is true in some cases, but because machines and tools depreciate and their efficiency reduces during time, this assumption cannot be true in all cases. In addition, in some industries like steel industry, jobs delay for process results in longer processing time. These kinds of jobs are introduced as deteriorating jobs, so a job is deteriorating whenever its processing time is not constant and is dependent on scheduled jobs. In this thesis, scheduling problems with deteriorating jobs are studied. A general classification of these problems is presented and literature review is studied. Then, flowshop scheduling with deteriorating jobs is discussed, and minimizing the number of tardy jobs is assumed as objective function. It is proven that the complexity of the problem is NP-hard. Therefore, a heuristic algorithm is proposed to achieve near optimum solution in a short time. Besides, an exact branch and bound algorithm, along with utilizing heuristic algorithm as upper bound, was proposed to achieve an optimal solution. Computational results demonstrate that branch and bound method solves problems with 24 jobs in the set High and 22 jobs in the set Low in a reasonable time. Results show that a high percentage of nodes are fathomed by lower bounds and dominance rules that shows the capability of the branch and bound algorithm. Also, it is shown that the average ratio of optimal solution to the heuristic one is at most 1.15 which is smaller in contrast with other studies in the related field in the literature. Finally, according to the efficiency of the presented approach, sample problems with large dimensions are generated and solved and their results are displayed.
عنوان نشريه :
مهندسي صنايع و مديريت شريف
عنوان نشريه :
مهندسي صنايع و مديريت شريف
