M&SOM Review

A seldom-publicized reality of brick-and-mortar retail is that most retailers do not know exactly what is on their shelves. Most retailers do maintain electronic inventory records reflecting incoming shipments and sales, but in practice these records fail to accurately represent the states of shelves for a variety of reasons.

View Full Post »

In a recent article in the Seattle Times (March 22, 2015), Jon Talton wrote about the United States' lack of focus on infrastructure projects, citing our failing bridges, tunnels, and transportations systems that have resulted in an infrastructure that has deteriorated to a level that is both dangerous and socially inefficient. According to Talton, "Americans, the people who built six transcontinental railroads, Grand Coulee and Hoover dams, and the Interstate Highway System....have lost their way".

View Full Post »

In the past decades, supply chain disruptions have caused significant losses to companies, and the severity and frequency of natural or man-made disasters are still increasing. The reliability and resilience of supply chains depend heavily on decisions made during the design phase when facilities such as suppliers, distribution centers, and retail outlets are strategically located. In order to design a reliable supply chain, one needs to consider both primary facilities that provide supply or service under normal conditions, and backup facilities that will serve customers whose primary facilities are unavailable during disruptions. New optimization methods have been developed to design supply chains that are both cost-effective and reliable.

View Full Post »

To enhance quality performance in supply chains, vendors must develop organizational knowledge to identify and address quality issues. However, such organizational knowledge can depreciate with time (just like physical assets). Depreciation of organizational knowledge in supply chains can have significant implications: quality performance can degrade, and resolved quality issues can resurface.

View Full Post »

High-speed rail (HSR) is arguably America’s most ambitious infrastructure project of the century. In 2009, as part of the American Recovery and Reinvestment Act, the federal government committed billions of dollars for projects to “jump-start a potential world-class passenger rail system.”

Over 30 states received federal funding covering 13 rail corridors. Among them, the largest project is the $68 billion California High-Speed Rail network that aims to connect San Francisco to Los Angeles with a ride that will take less than three hours. The state rail authority released a draft request for proposals and broke ground in Fresno in January 2015.

View Full Post »

Relative to brick-and-mortar retailers, online retailers can offer to their customers a wider product assortment and more delivery-time choices. The online retailer can do this by operating a distribution network with geographically-dispersed fulfillment centers (FCs) and with a centralized control system. This allows the online retailer to assume more control in how customer orders are filled, relative to a traditional retailer. The online retailer, not the customer, decides from where items will ship, by what shipping method, and how or whether multiple-item orders will be broken up into multiple shipments. For a given order, the online retailer wants to incur as little outbound shipping costs as possible, as the customer often pays a flat fee for shipping or pays nothing. Outbound shipping costs – the costs to ship packages from the online retailer to customers via FedEx, UPS, USPS, or local courier – are significant, often exceeding the retailer’s profits. Given this, what is the best way to fulfill each customer’s order to minimize average outbound shipping cost?

View Full Post »

Our research on expediting policies was motivated by an inventory optimization problem that we encountered at a major equipment manufacturer. The manufacturer asked us to analyze the inventory performance of the spare parts network. We started with an analysis of the inventory performance at the central warehouse and collected data on demands, lead times, and lead time variability. We then used the standard inventory optimization approaches, which assume that lead time variability is caused by external factors, such as delays in the manufacturing processes of suppliers. In these models, lead times are independent of the inventory levels at the central warehouse.

View Full Post »

In 2011, President Obama set an ambitious goal of making the United States the first country to have 1 million electric vehicles on the road by 2015. With this goal, both the Federal and state governments have invested heavily in the industry through various sources of incentives and subsidies directed at its various stakeholders, notably including the $2.4 billion Federal grant approved in 2011.

View Full Post »

Motivated by the trend towards more collaboration in workflows, we study service and manufacturing networks where some tasks require the simultaneous processing by multiple types of multi-tasking human resources. By simultaneous collaboration we mean that some activities require the simultaneous processing by multiple types of resources. Discharging a patient, for example, may require the presence of both a doctor and a nurse. Multitasking means that a resource performs multiple activities. Multitasking is equivalent to resource sharing, which means that multiple activities require the same resource. A doctor, for example, may be required for both patient diagnosis and patient discharge. Simultaneous collaboration imposes constraints on the capacity of the process because multitasking resources have to be simultaneously at the right place. The effects of these resource synchronization requirements are more pronounced in human-operated settings in which resources cannot be “split.” An emergency room doctor may split her time between multiple activities—spending x % of her time in one activity and the remaining (100 – x)% in another—and she may switch between the activities frequently, yet she cannot process both activities at the same time (which may, in this example, require her physical presence in two distinct locations). We study how collaboration requirements affect the process capacity (in the example, this corresponds to the number of patients that can be treated per hour).

View Full Post »

The motivation of this new online initiative is due to the fact that M&SOM Journal articles are written for OM researchers primarily. Consequently, non-OM researchers are often unable to see through the thicket of technical analysis; unable to appreciate the relevance of various M&SOM articles; and unable to apply the research findings of many M&SOM articles that could influence research in other fields or OM practice.

View Full Post »