Simulation And Optimization On RFID-enabled CONWIP Control Strategy For Multi-Echelon Distribution System

The control strategies on multi-echelon systems are widely concerned by the academic communities in recent years.However,the inventory levels of supply chain are affected deeply by a lot of uncertain and stochastic factors,and this will inevitably cause too high storages or too low service levels consequently.CONWIP is a production control strategy applicable in many manufacturing environment,that uses cards to control WIP evel.The CONWIP strategy focuses on controlling WIP in the system.It is simpler in the sense that only a single card count setting is required instead of a card count for each workstation.As an alternative to kanban,CONWIP system has some superior characteristics over the Kanban system.Some scholars applied the CONWIP control strategy to the multi-echelon inventory system of supply chain in recent years.However,the Card system cannot be really applied in supply chain,the CONWIP control strategy is the "order pull" or "contract pull" virtually,it is difficult to give full play to the function of decreasing inventory levels and raising the serve levels.The emergence of the internet of things and radio frequency identification(RFID)provide an efficient way to performance improvements of the supply chain.as the technology of RFID can count and locate the inventory products and goods transited precisely,the appearance of RFID provides a technique method that RFID-enabled electronic Card system is remote real time visual,therefore,the CONWIPcontrol strategy can be realized for multi-echelon inventory systems in supply chain distribution network.The supply chain system is a kind of complicated system,each enterprise in supply chain is influenced by many uncertain factors.Thus,the analytical methods cannot be used to solve the problem of multi-echelon inventory networks in supply chain with complex changes effectively.The simulation method is an ideal tool to study it.However,the simulation method is not a kind of optimization method,it cannot give the optimal solution or satisfactory solution of the problem,the simulation method and the optimization technology need to be combined to form SBO(Simulation-based Optimization)method,which is a better way to solve the complex stochastic system optimization problem.In this dissertation,the RFID-enabled CONWIP control strategy for multi-echelon inventory system in supply chain distribution networks is designed based on the RFID-enabled electronic Card system.In addition,three-echelon inventory systems of supply chain are exemplified.To evaluate the impact of control strategies on supply chain distribution network performance,the assessment index system is designed.All kinds of strategies are compared,verified and optimized based on the simulation platform and the SGHS(Self-adaptive harmony search algorithm)optimization method.It has potential to the practical applications of RFID-enabled CONWIP control strategy.The whole dissertation contains the following aspects:(1)RFID-enabled electronic Card system is developed and realized based on the RFID,which can count and locate the inventory products and goods transited precisely.The total design of the system and hardware realization is studied.The works metioned above provide the foudnation for RFID-enabled electronic Card system to play full role in the multi-echelon inventory networks of supply chain.(2)On the basis of lessons from effective CONWIP control strategy in the single factory multi-stage production storage system,three-echelon inventory systems in supply chain are exemplified,the RFID-enabled CONWIP control strategy is designed based on the RFID-enabled electronic Card system and the mathematical model is established.The structure characteristics of the supply chain and the functions of node enterprises in different echelons are considered in the strategy design.(3)The performance assessment indexes system of multi-echelon inventory control in supply chain is designed and the simulation platform is developed.The various of inventory control strategies are compared on the simulation platform adopting the designed performance assessment indexes system.(4)The simulation-based optimization method is adopted to optimize the CONWIP strategy using the simulation platform.The SGHS is the upper level optimization algorithm,and the optimal solutions prove the feasibility of the scheme.The CONWIP strategy is compared with other traditional strategies under different structural multi-echelon inventory systems of supply chain distribution network.simulation results show that the RFID-Enabled CONWIP strategy is effective and superior in the distribution network management.