طراحي، يكپارچه يك زنجيره تامين سه سطحي با تقاضاي تصادفي

چكيده انگليسي :

Integrated design of a three level supply chain with stochastic demand Hossein Kamandi h kamandi@in iut ac ir Date of Submission 2013 04 17 Department of Industrial Engineering Isfahan University of Technology Isfahan 84156 83111 Iran Degree M Sc Language Farsi Supervisor Farimah Mokhatab Rafiei Farimah@cc iut ac ir Abstract This study is a facility location and task allocation problem of a three level supply chain under stochastic demand for one such product in a period of time with lead time and inventory costs at the strategic and tactical levels Consisting of plants distributors wholesalers and retailers and three level supply chain is selected because the literature in this area is weak Decisions include locating a number of production facilities and distribution centers among a finite set of potential sites and allocation of tasks between production centers and distribution centers and retailers demand for minimizing costs that the costs include the cost of establishing plants and distribution centers and maintenance cost of products in distribution centers and transportation costs of goods In addition to ordering cost per unit time is considered Remember also to consider the safety stock for all distribution center the model include the maintenance cost of safety stock Stochastic demand for goods to be sent to distribution centers by the demand centers and from there ordered to the plants or plant Each retailer the amount of product needed only one distribution center receives and it is impossible to send the products directly from the plants to retailers As well as distribution centers product requirements based on demand content received from retailer or retailers make to order plant and received goods stored in their warehouses and then sending them to demand centers since customer demand is random and is assumed to follow a normal distribution with mean and variance given the value safety stock in the distribution center to prevent unforeseen shortages of goods is maintained Also for consider the stochastic demand five demand scenario has been developed Demand of retailers in each scenario is represented as a vector that the demand vectors follow a normal distribution with equal mean and different variance Finally the best scenario is to have the lowest value of the objective function is selected as the answer to every problem An important feature of this model consider the selectable levels of capacity for the distribution centers that lead to flexibility in determining the size of the distribution centers This is a integer programming model is formulated to be integrated and exact solution for small sized problems using Lingo software is provided Also given that the problem is NP Hard a meta heuristic algorithms such as genetics to solve this problem have been proposed The results obtained from genetic algorithm and compare it with the results obtained from Lingo software solution for small sized problems indicate the effectiveness of the proposed genetic algorithm Keywords Three level supply chain Stochastic demand Capacity levels Genetic algorithm PDF created with pdfFactory trial version www pdffactory com

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طراحي، يكپارچه يك زنجيره تامين سه سطحي با تقاضاي تصادفي

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