مدل سازي مساله طراحي سيستم توليد سلولي با برنامه ريزي چند هدفه فازي تعميم يافته

Modeling a Manufacturing Cell Design Problem with Extended Fuzzy Multi-Objective Programming

اين مقاله يك مدل برنامه ريزي رياضي چند هدفه عدد صحيح فازي جديد براي مساله طراحي سيستم هاي توليد سلولي و متدولوژي هاي حل آن را ارايه مي دهد. هدف مدل پيشنهادي به كارگيري دو مساله مهم طراحي سيستم توليد سلولي به نام تشكيل سلول و عناصر استثنايي براي طراحي كارآمد و بهتر سيستم هاي توليد سلولي است كه به طور همزمان در محيط فازي مي باشند. يك طراحي موثر سيستم توليد سلولي به ملاحظات همزمان ويژگي هاي عمر واقعي و زمان واقعي مناسب براي سيستم نياز دارد. توابع هدف مدل عبارتند از: حداقل كردن هزينه حذف عناصر استثنايي، حداقل كردن تعداد عمليات هاي خارجي سلول و حداكثر كردن بهره برداري ظرفيت ماشين. پارامترهاي فازي مدل، تقاضاي قطعه، ظرفيت ماشين، زمان پردازش، بودجه و هزينه هاي حذف عناصر استثنايي هستند. مديريت، رسيدن همزمان به راه حل هاي بهينه براي همه توابع هدف را مي خواهد. براي نمايش مدل، يك مثال عددي با حدود فازي از ادبيات تحقيق در نظر گرفته شده است و نتايج محاسبات و تحليل حساسيت به وسيله حل مدل بدست مي آيند. همچنين دو معيار عملكرد ويژه براي مساله پيشنهاد مي شوند و راه حل هاي مدل با استفاده از اين معيارهاي عملكرد بررسي مي شوند. مدل قادر به بيان ابهام همه پارامتر هاي سيستم است و مدل طرح هاي تصميم مختلفي را به تصميم گيرنده براي درجه هاي مختلفي از دقت مي دهد.

Nowadays, management tends to decision making via some techniques according to environmental conditions. It is obvious that the condition of decision making is inexact and vague in organic environments and data are mainly vague and uncertain. Decision making is a difficult process in conditions of uncertainty and vagueness in the manufacturing system. In this situation, it seems that fuzzy methodologies are more suitable tools to fuzzy considerations. This paper presents a new fuzzy integer multi-objective mathematical programming model for the cellular manufacturing systems (CMS) design problem and its solution methodologies. The aim of the proposed model is to handle two important problems of CMS design called cell formation and exceptional elements simultaneously in fuzzy environment for efficient and better CMS design. An efficient CMS design requires concurrent consideration of real life and real time features relevant to the system. The objectives of the model are minimization of the cost of exceptional element elimination, minimization of the number of outer cell operations and maximization of the utilized machine capacity. The model fuzzy parameters are part demand, machine capacity, processing time, budget and the exceptional elementsʹ elimination costs. Management wants to reach simultaneous optimal solutions for all objective functions. To illustrate the model, an example problem with fuzzy extension is adopted from literature and computational result and sensitivity analysis are obtained by the new solving model. Also, two well-known performance measures are suggested for this problem and model solutions are investigated by using these performance measures. The model is capable of expressing vagueness of all the system parameters and gives the decision-maker (DM) alternative decision plans for different grades of precision. Keywords: Cellular Manufacturing System, Group Technology, Cell Formation, Exceptional Elements, Multi Objective Programming, Fuzzy Mathematical Modeling.