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  • [ X ]
    Öğe
    Analysis of fuzzy supply chain performance based on different buyback contract configurations
    (Springer, 2020) Canbulut, Gülçin; Torun, Hulya
    In this study, a two-echelon supply chain is analyzed where the supplier sells the products to retailer, who in turn sells the product to end customers. In such an arrangement, the supplier and the retailer aim to increase their profits individually which causes double marginalization. Several studies have been proposed by researches to solve the problem of double marginalization'' and its consequences to supply chain performance. Therefore, contractual agreements as coordination mechanisms were developed to improve the supply chain performance. In the literature, many studies have been conducted on these coordination mechanisms under probabilistic demand. However, in the absence of the historical data it is not possible to establish the probability distribution. In such cases, the fuzzy set theory which is another illustration of uncertainty can be used to model the supply chain. In this study, different configurations of buyback contracts on supply chain performance under fuzzy environment are analyzed. Initially, closed-form solution to buyback contract model with fuzzy demand is proposed by using credibility theory. After that, the closed form of this model with fuzzy buyback rate parameter is obtained. And then the effects of the different configurations of the buyback contract model are analyzed by changing the buyback rate and buyback price. Finally, numerical examples are presented to demonstrate the solving processes of the models and the different effects of buyback rate and buyback price on parameters of buyback contract and the fuzzy expected profit value of all members in supply chain.
  • [ X ]
    Öğe
    Analysis of two stage supply chain coordination under fuzzy demand
    (Gazi Univ, Fac Engineering Architecture, 2019) Torun, Hulya; Canbulut, Gülçin
    In this study; a two-stage supply chain structure consisting of a supplier and a retailer has been investigated when the demand variable is a fuzzy parameter. Each of the supply chain members has different goals and wants to optimize their performance. Thus coordination between the supply chain members must be confirmed. According to this coordination, supply chains are classified into centralized and decentralized supply chains. For the centralized and decentralized supply chain models, generalized closed-form solutions of optimal order quantity and supply chain members profit functions are obtained using the expected value function and credibility theory when the demand parameter is a fuzzy variable. Then, in addition to the demand fuzziness, when the wholesale price is also considered as a fuzzy variable, supply chain members and supply chain total profits have been obtained for the decentralized supply chain model. Finally, proposed models are analyzed under numerical examples.
  • [ X ]
    Öğe
    Performance Evaluation of a Two-stage Supply Chain Under Fuzzy Environment
    (Old City Publishing Inc, 2018) Torun, Hulya; Canbulut, Gülçin
    In this paper, performance evaluation of a two-stage supply chain which consists of a supplier and a retailer under uncertainty environment is examined. In the literature; many studies have been investigated on supply chain performance analysis in uncertainty environment and demand parameter is an essential data on these analyses. When there is sufficient data about demand, it is easy to construct probability distribution of demand. However, in the absence of enough historical data, it is impossible to construct the probability distribution. The demand parameter is intuitively determined and shown by a fuzzy distribution in such situations. This paper intends to find closed form solutions in order to maximize the performance of a two-stage supply chain with coordination under fuzzy environment. The coordination of the supply chain is maintained by contracts. The contracts analysed in this study are revenue sharing contract and buy back contract. Numerical examples are presented to show the validity of the proposed models and to investigate the effect of contract parameters on the total performance of the supply chain.