Department of Industrial Engineering, KNT University of Technology, Tehran, Iran
We investigate a one-buyer-multi-vendor co-ordination model with vendor selection problemin a centralized supply chain. In the proposed model, the buyer selects one or more vendorsand orders an appropriate quantity. The quantity discount mechanism is used by all vendors with the aim of coordinating the supply chain. We formulate the problem as a multi objective mixed integer nonlinear mathematical model. Using the Global Criterion method, the proposed model is transformed into a single objective optimization problem. Since, the problem is NP-hard, we propose four meta-heuristic algorithms: Particle Swarm Optimization (PSO), Scatter Search (SS), Population based Harmony Search (HS-pop) and Harmony Search based Cultural Algorithm (HS-CA). The Taguchi’s robust tuning method is applied in order to estimate the optimum values of parameters. Then, the solution quality and computational time of algorithms are compared.