An EOQ model with multiple suppliers and random capacity

We consider an EOQ model with multiple suppliers that have random capacities, which leads to uncertain yield in orders. A given order is fully received from a supplier if the order quantity is less than the supplier's capacity; otherwise, the quantity received is equal to the available capacity. The optimal order quantities for the suppliers can be obtained as the unique solution of an implicit set of equations in which the expected unsatisfied order is the same for each supplier. Further characterizations and properties are obtained for the uniform and exponential capacity cases with discussions on the issues related to diversification among suppliers. © 2005 Wiley Periodicals, Inc. Naval Research Logistics, 2006     

The Shifting Determinants of Defense Spending Preferences Between 1980 and 2008

This paper analyzes defense spending preferences using ordered logit regression analysis of American National Election Survey data from 1980 through 2008. Our results indicate that as opposed to having the ideology of isolationism, political party identification towards the Republican Party or having economic stakes in defense spending always play a significant role in increased preference towards defense spending. Demographic groups such as Native Americans, Hispanics, and retired women, a demographic subgroup, display generally positive preferences towards defense spending. Somewhat surprisingly, another demographic subgroup, ‘security moms,’ do not show a preference. Our analysis also displays lower (higher) preference in the early 1990s (2000s) for defense spending compared to the year 2008.     

Outbound supply chain network design with mode selection and lead time considerations

We present a large‐scale network design model for the outbound supply chain of an automotive company that considers transportation mode selection (road vs. rail) and explicitly models the relationship between lead times and the volume of flow through the nodes of the network. We formulate the problem as a nonlinear zero‐one integer program, reformulate it to obtain a linear integer model, and develop a Lagrangian heuristic for its solution that gives near‐optimal results in reasonable time. We also present scenario analyses that examine the behavior of the supply chain under different parameter settings and the performance of the solution procedures under different experimental conditions. © 2006 Wiley Periodicals, Inc. Naval Research Logistics, 2007