طراحي يك مدل يكپارچه استوار دو هدفه زنجيره تامين و آرايش سلولي مجازي پويا

Designing a robust bi-objective mathematical model for integrated supply chain planning and dynamic virtual cell formation

در يك محيط پويا، تغييرات تقاضا در طول افق برنامه ريزي در دوره هاي مختلف رخ خواهد داد. آرايش سلولي در يك دوره ممكن است براي دوره هاي ديگر موثر نباشد. از اين رو، پيكربندي مجدد سلول ها ضروري به نظر مي رسد. مفهوم آرايش سلولي مجازي رويكردي جهت مواجهه با تغييرات تقاضا بدون تحميل هزينه هاي پيكربندي مجدد به سيستم است. از طرف ديگر، در نظر گرفتن همزمان زنجيره تامين و آرايش سلولي منجر به كاهش هزينه هاي توزيع و توليد و پاسخگويي بهتر به تقاضاي بازار مي شود. در اين تحقيق، يك مدل رياضي دوهدفه استوار جهت يكپارچه ســازي برنامه ريزي تداركات، توليد و توزيع در شرايط عدم قطعيت توسعه داده شده است. سپس، از روش محدوديت اپسيلن تعميم‌يافته جهت حل مدل پيشنهادي بهره گرفته شده است. در نهايت، يك مطالعه موردي صنعتي جهت اعتبارسنجي مدل پيشنهادي ارايه شده است. نتايج به دست آمده توسط مديران و طراحان مورد تصديق قرار گرفته است.

Cell formation, as one of the most important decision problems in designing a cellular manufacturing system, consists of grouping parts into part families and machines into cells. In a dynamic environment, the part demand/mix change is considered over a planning horizon divided into periods. Hence, the formation of cells for one period may no longer be effective for other periods and therefore, reconfiguration of cells is essential. Due to the variation of demand and the need for cells reconfiguration, virtual cell formation concept is introduced by researchers to take the advantage of cell formation without incurring reconfiguration charges. On the other hand, Simultaneous consideration of supply chain issues and cell formation results in lower distribution and procurement costs and faster response to customers. In traditional manufacturing systems, first, the supply chain is designed, the number of production facilities is determined and the facilities are assigned to support each market for each product; then, the organization of the processes (product line, process or cell formation) within factory is decided.In this paper, a new bi-objective robust optimization mathematical model is developed for integrating procurement, production and distribution planning considering various conflicting objectives simultaneously as well as the uncertainty of some critical parameters such as customer demands. Theaugmented ?-constraint method is utilized to solve the proposed mathematical model and to find a preferred compromise solution. Moreover, a real world industrial case is provided to justify the applicability of the proposed model.