Bayi yer seçimi problemi

In this study, we aim to design a distribution system with the following components:the location of vendors, the number of vendors, the service region ofthe vendors, the number of vehicles and workers, and the assignment of demandpoints to these vendors and vehicles. We define our problem as a two-level capacitateddiscrete facility location problem with minimum profit constraints andcall it Vendor Location Problem. In order to formulate the problem, two differentobjective functions are used: vendors?s profit maximization and maximization ofthe demand covered. Integer linear programs for these two versions of the problemare formulated. Valid inequalities are used to strengthen the upper bounds.Finally, the performance of these models with different parameters are comparedin terms of linear programming relaxation gap, optimality gap, CPU time, andthe number of opened nodes for four different types of instances: instances withdemand and profit which are independent of distance; profit function of distance;demand function of distance; demand and profit function of distance.