Bullwhip Effect Restraint In Closed- Loop Supply Chain With Hybrid Recycling Channels

With the introduction of low-carbon economy and sustainable development strategy, the reverse logistics and the remanufacturing play an increasingly important role in the environment and economic activity. At the same time, the recovery process is complex so that the hybrid recycling is imperative. And there are more disturbance factors in the closed-loop supply chain with hybrid recycling channels, such as:the uncertain cost parameters of the recycled process in the hybrid recycling channels, the uncertain disposal cost parameters and the lead times in the hybrid recycling channels and so on. These factors will exacerbate the bullwhip effect of the closed-loop supply chain. Therefore, based on the above analysis, the impacts which caused by the uncertainty, the lead time and combine the uncertainty with the lead time respectively on the bullwhip effect are considered. And, three kinds of the closed-loop supply chains with hybrid recycling channels models are established. Then, the fuzzy robust control methods are proposed to restrain the bullwhip effect of the closed-loop supply chain. Moreover, these methods can make the closed-loop supply chains with hybrid recycling channels remain robust stability. The main research work includes:(1) The restraint of bullwhip effect caused by the uncertainties is studied in the closed-loop supply chain with hybrid recycling channels. Firstly, the basic models of the closed-loop supply chain with hybrid recycling channels are established where the manufacturer and the third party recovery provider collect the recycled products at the same time. Based on the basic models, the impacts of the uncertainties are considered, and construct the uncertain closed-loop supply chain with hybrid recycling channels. Then, the uncertain closed-loop supply chain models are converted into a nonlinear fuzzy switching model based on the discrete Takagi-Sugeno(T-S) fuzzy control system. Secondly, a fuzzy robust control method is utilized to reduce the impacts caused by the internal and external uncertain factors on the closed-loop supply chain. This method can not only restrain the bullwhip effect, but also make supply chain remain robust stability. Finally, the simulation results show the feasibility and effectiveness of the utilized fuzzy control system.(2) The restraint of bullwhip effect in closed-loop supply chain with lead times based on hybrid recycling channels is studied. Firstly, based on the basic models of the closed-loop supply chain with hybrid recycling channels, the impacts of lead times on the bullwhip effect are considered, and the closed-loop supply chain models with lead times based on hybrid recycling channels are established. Secondly, a T-S fuzzy model with lead times is constructed based on the discrete T-S fuzzy control system. Moreover, in order to restrain the bullwhip effect effectively, a new fuzzy robust H? control method is proposed. Finally, compared with the common robust control method, the simulation results show that the fuzzy robust control method can not only more effectively restrain the bullwhip effect, but also make the total cost of the closed-loop supply chain lower.(3) The restraint of bullwhip effect caused by the uncertainties and lead times is studied in the closed-loop supply chain with hybrid recycling channels. Firstly, based on the basic models of the closed-loop supply chain with hybrid recycling channels, the impacts of lead times and uncertain system parameters on the bullwhip effect are considered, and the uncertain closed-loop supply chain models with lead times based on hybrid recycling channels are established. Then, the above models are converted into a nonlinear uncertain closed-loop supply chain fuzzy switching model with lead times based on the discrete T-S fuzzy control system. Secondly a new fuzzy robust Hx control method is proposed for the T-S fuzzy model. This method can make the cost parameters, the control variables and the state variables remain robust stability, so that the bullwhip effect is restrained.