On-time Delivery Model In Assembly System With Vendor-managed-inventory Policy

This dissertation investigates a decentralized assembly system with VMI policy by applying a series of methodologies:management, operation research, system decision making, optimization modeling, qualitative analysis and quantitative analysis. The following topics are addressed:First, I construct an on-time delivery model consisted of multi-suppliers and single manufacturer, in condition of an uncertain demand time. The results indicate that information sharing can effectively improve the supplier’s and the channel’s performance. This subsequently highlights the significance of horizontal information, so that every supplier has the incentive of sharing the supply information.Second, I investigate the multi-suppliers’on-time delivery model in consideration of the inventory controlling policy. The results show that the traditional VMI policy is never an eternal better choice for either the manufacturer or the supplier, even though there is only one supplier in the system. In a more complicated assembly system with multiple suppliers, I derive the manufacturer’s optimal inventory controlling policy and supplier’s optimal deliver time, so as to provide the coordination strategy for the entire supply chain.Third, I address different payment contracts in a decentralized system, so as to extend the analysis from the downstream uncertainty to the upstream uncertainty. The results show that there is no better payment for either the manufacturer or the supplier, which is in strict contrast to the practice. I also consider the N suppliers system and discuss the coordination conditions under this circumstance.Fourth, I consider an assembly system that contains two different deliver modes:pull and push. The results derive the optimal supplier and demand strategies under two decision timing sequences. Moreover, by comparing the supply chain performance under different modes, I provide the coordination mechanism to achieve the perfect coordination.Finally, I discuss the operational mechanisms for the assembly system, in particular consider two typical assembly system operating modes:Supply-hub and VMI modes. Compared to the VMI mode, I find that Supply-hub can significantly improve the supply chain performance, and identify the appropriate conditions for using these operational mechanisms. All the above results can provide some theoretical support for the firms’ practices.