مدل‌سازي و حل يك مسيله‌ي دوباره‌كاري توليد با استفاده از رويكرد صف

Modeling and Solving a Remanufacturing Problem within Queuing Approach

دوباره‌كاري توليد، فرايندي است كه طي آن محصولات مستهلك يا معيوب با شرايط يك محصول جديد بازيابي مي‌شود. قوانين محيط زيست، انتظارات مشتريان، و محرك‌هاي اقتصادي از مهم‌ترين عوامل ايجاد انگيزه در صنايع براي استفاده از فعاليت‌هايي نظير دوباره‌كاري توليد و بازيافت هستند. در اين پژوهش يك مدل دو‌هدفه1 PINLP براي به دست آوردن تعداد بهينه‌ي ماشين‌آلات مورد نياز هر‌يك از ايستگاه‌هاي كاري در يك مركز دوباره‌كاري توليد ارايه شده است. يكي از اهداف ارايه‌شده در اين مدل، كمينه‌سازي متوسط زمان انتظار محصولات در صف است؛ هدف ديگر كمينه‌سازي متوسط بيكاري‌هاي ايستگاه‌هاي كاري است. مدل ايجاد شده توسط روش‌هاي LPسنجي و Maximin حل شده و به‌دليل پيچيدگي بسيار بالاي مدل مثال‌هايي با ابعاد كوچك براي آن ارايه شده است. در انتها جواب‌هاي حاصل از روش‌هاي مذكور ارايه شده است.

Remanufacturing is an industrial process in which worn-out products are restored to like-new conditions. Environmental considerations, government regulations, and economic incentives motivate many businesses to engage in recovery activities. In recent years, more and more companies have initiated value-added recovery operations such as remanufacturing. Remanufacturing brings a product or product part up to an as-new quality. Since remanufacturing is often cheaper than manufacturing, this type of recovery can lead to considerable cost savings. Remanufacturing is an important element of product recovery. Product recovery management is concerned with the collection of used and discarded products and the exploration of the opportunities to remanufacture the products, reuse the components or recycle the materials. Remanufacturing is not only a direct and preferable way to reduce the amount of waste generated, it also reduces the consumption of new materials and energy resources. In this study we have introduced a multiple objective PINLP model that uses queueing theory to find the optimum number of machines in each station of remanufacturing facility. In our model , returned products (Products that returns for any reason such as unsatisfying consumers , used products and etc) comes to the testing station and after inspection the appropriate station is selected. This productions make a queue before entering to the stations and then the operation that is needed in a specific station is occured. the first objective function is minimizing the average waiting time in queue that is important for time sensitive products . the second objective function is minimizing the average idle time of stages . for this model we have used two methods to solve it. First method is L-P metric with two parameter p=1 and p=2 and the second method is Maximin. Due to the complexity of this nonlinear model we have represented two small instances , solved it with Lingo 11 and the results have been shown .