Daniel Y. Mo

Design of inventory pools in spare part support operation systems

The objective of a spare part support operation is to fulfill the part request order with different service contracts in the agreed response time. With this objective to achieve different service targets for multiple service contracts and the considerations of inventory investment, it is not only important to determine the inventory policy but also to design the structure of inventory pools and the order fulfilment strategies. In this research, we focused on two types of inventory pools: multiple inventory pool (MIP) and consolidated inventory pool (CIP). The idea of MIP is to maintain separated inventory pools based on the types of service contract, while CIP solely maintains a single inventory pool regardless of service contract. Our research aims to design the inventory pool analytically and propose reserve strategies to manage the order fulfilment risks in CIP. Mathematical models and simulation experiments would be applied for analysis and evaluation.

Flow Diversion Strategies for Routing in Integrated Automatic Shipment Handling Systems

The integrated automatic shipment handling systems (IASHSs) in large freight terminals and distribution centers are complex and increasingly congested due to the increase of freight volume. Shipments in IASHS need to be handled by a large amount of equipment. Thus, optimization-based tactical and operational planning models and methods for how the shipments are routed through the network of equipment in IASHS are required. To reduce the total shipment travel time, this paper studies a flow diversion strategy for routing shipments from their origins to their destinations, using multiple paths. This strategy is further leveraged to develop a destination reassignment strategy and time control strategy. We formulate these strategies as mathematical models and evaluate their effectiveness in static and adaptive implementations via numerical experiments. They are also compared to the classical shortest path oriented strategies.

Flow diversion approaches for shipment routing in automatic shipment handling systems

The integrated automated shipment handling systems (IASHS) in large freight terminals and distribution centers are complex and are increasingly congested due to the increase of freight volume. Shipments in IASHS need to be handled by a large amount of equipment. Thus, optimization-based tactical and operational planning models and methods for how to route the shipments through the network of equipment in IASHS are required for reducing the shipment transit time. This paper studies a static and an adaptive flow diversion approaches for routing shipments from their origins to their destinations. The approaches are compared to the classical shortest path oriented strategies. Furthermore, the paper investigates the possibility of using the proposed approaches to determining the destination of a shipment dynamically

Mass Customizing Spare Parts Support Services Based on Response Time With Inventory Pooling Strategies

Spare parts support services have received increasing management attention due to the growing number of critical systems in many business sectors. In this paper, we examine an integrated system design approach to customize spare parts support services based on response time with inventory pooling strategies. To provide customized services that meet user requirements for spare part response time, we depart from the traditional spare parts management and develop a systematic approach to design service parts support services based on axiomatic design theory. In particular, we focus on pricing discrimination decisions in service parts contracts for two-tier users under a mechanism design framework. Distinguishing between users of next-day and same-day contracts for service parts operations, we further evaluate the effect of various inventory pool structures with reserve strategies through a simulation model for the objective of cost minimization. These analytical results of this new approach provide guidance for managers in customizing spare parts support services with the holistic consideration of pricing scheme, response time, and inventory policy.