چكيده به لاتين
Abstract:
This study express the design of a bicycle sharing system with regards to the considerations of covering problems and inventory level related to the satisfactory level of the customers for this system. In addition we could consider establishment of support & service centers with covering behaviour in order to maintain and repair the inventory of bicycles in the stations in this study. Furthermore, a mathematical MODM model is provided so that the first objective is to maximizing the total profit of the system, and the second one is the maximum customer’s satisfication. The mathematical model of this problem in this study is based on hub location problem models. The main decision variables addressed in this model are inclusive of number and locations of bicycle stations, number and locations of support & service centers, selscting optimized paths between stations and in order to move from origins to destinations, establishing bicycle lanes between stations, determining how the bicycle stations allocated to the support & service centers, and also the maximum customer’s satisfication.
The mathematical formulation has the integrated view so that the benefits for both investor and users has been considered simultaniously in this problem. A numerical example has been given in this study in order to illustrate the mathematical formulation in the practical real world situation. The provided mathematical model is NP-Hard, and it is difficult to have an exact solution, therefore in the numerical example in small scale the inventory decision variable which is based on poisson distribution, has been estimated by standard normal distribution. The main part of the model, except inventory restriction, is MIP (Mixed Integer Programming), therefore by using GAMS software with the solver of CPLEX, the exact solutions for this linear part is given. We have implemented sensitivity analysis on MODM model in order to illustrate the impact of weight parameter for the first and second objectives.
Keywords:
Bicycle Sharing System, Hub Location Problem (HLP), covering problem, Inventory level
