عنوان مقاله :
رويكرد واكنشي باثبات براي زمان بندي آني سيستم جريان كارگاهي انعطاف پذير با شرط پذيرش يا رد سفارش هاي غيرمنتظره
عنوان به زبان ديگر :
A STABLE REACTIVE APPROACH TO ONLINE SCHEDULING FOR FLEXIBLE FLOW SHOP SYSTEM WITH ACCEPTANCE OR REJECTION OF UNEXPECTED ORDERS
پديد آورندگان :
رحماني، دنيا دانشگاه صنعتي خواجه نصيرالدين طوسي - دانشكده مهندسي صنايع
كليدواژه :
زمان بندي آني , اختلال , مقياس هاي جاي گزين , ثبات , زمان بندي واكنشي
چكيده فارسي :
درمسائل زمان بندي اختلالات غيرمنتظره يي رخ مي دهد كه باعث مي شود يافتن جواب هاي باثبات حتي نسبت به يافتن جواب هاي بهينه كاراتر باشد. تاكنون در مواجهه با چنين اختلالاتي، يا از روش هاي مبتني بر شبيه سازي استفاده شده است كه بسيار وقت گيرند يا مقياس هاي جاي گزيني توسعه داده شده اند كه تقريبي از شرايط واقعي سيستم بعد از اختلال را پيش بيني مي كنند كه ضعف هاي زيادي دارند.
در اين مقاله براي به دست آوردن زمان بندي باثبات، در برابر اختلالاتي كه به صورت ورود غيرمنتظره و پيش بيني نشده ي كارهاي جديد است، يك رويكرد نوين واكنشي چندهدفه ارائه شده است كه بعد از هر اختلال به زمان بندي مجدد سيستم مي پردازد و عملكرد آن با يك مطالعه ي موردي در صنعت شيرآلات نفتي بررسي شده است. نتايج محاسباتي حاكي از آن است كه رويكرد پيشنهادي در برابر روش هاي موجود عملكرد بهتري دارد.
چكيده لاتين :
In industrial environments, scheduling systems often operate under dynamic and random circumstances. In these conditions, it is inevitable to encounter some disruptions and breakdowns which are inherently unexpected events. These disruptions bring about the initial schedule to quickly become infeasible and non-optimal and in need of appropriate revisions and rescheduling methods. We consider a flexible flow shop (FFS) system with stochastic or unexpected disruptions such as the arrival of new unpredicted jobs into the process. The occurrence of disruptions and unexpected events in scheduling problems makes
the obtaining of robust and stable solutions more valuable than the finding of optimal solutions that ignore these disruptions. In the literature, for achieving stable solutions, either iteration-based time-consuming simulation methods or surrogate measures (SMs) have been developed; they proactively provide an approximation of the system's real conditions following the occurrence of a disruption due to of the discrepancies of these measures with their true values; however, they may not show the true performance of the system. In this paper, a new reactive approach is considered to achieve a stable scheduling despite unpredicted disruptions, such as unexpected arrivals of new jobs. In this approach, a multi-objective reactive method based on classical and new performance measures is used to control the effects of disruptions that reschedule the initial plans after any unexpected event. An innovative concept called the ``Stability'' is introduced to reduce the effects of the unexpected disruptions. As the FFS problem is NP-hard, considering that stochastic disruptions increase its complexity, the non-dominated Sorting GA-II algorithm or NSGA-II, which is a very famous multi-objective optimization algorithm, is then applied to solve it. To show the performance of the proposed approach, a case study in petrochemical industry is considered. Computational results indicate that this method produces better solutions compared to the classical scheduling approaches used in this company.
عنوان نشريه :
مهندسي صنايع و مديريت شريف
عنوان نشريه :
مهندسي صنايع و مديريت شريف
