We consider the problem of scheduling n jobs to minimize the total earliness and tardiness penalty. We review the literature on this topic, providing a framework to show how results have been generalized starting with a basic model that contains symmetric penalties, one machine and a common due date. To this base we add such features as parallel machines, complex penalty functions and distinct due dates. We also consolidate many of the existing results by proving general forms of two key properties of earliness/tardiness models.

This paper examines supply chain design strategies for a specific type of perishable product—fresh produce—using melons and sweet corn as examples. Melons and other types of produce reach their peak value at the time of harvest; product value deteriorates exponentially post‐harvest until the product is cooled to dampen the deterioration. Using the product's marginal value of time (MVT), the rate at which the product loses value over time in the supply chain, we show that the appropriate model to minimize lost value in the supply chain is a hybrid of a responsive model from post‐harvest to cooling, followed by an efficient model in the remainder of the chain. We also show that these two segments of the supply chain are only loosely linked, implying that little coordination is required across the chain to achieve value maximization. The models we develop also provide insights into the use of a product's MVT to develop supply chain strategies for other perishable products.

Supply chain management (SCM) is concerned with the relationship between a company and its suppliers and customers. It is characterized by interorganizational coordination: companies working jointly with their customers and suppliers to integrate activities along the supply chain to effectively supply product to customers. More developed SCM is indicated by systematic integration, i.e. standardized and automatic interorganizational interfaces. Information technology (IT) engenders such systematic integration by allowing more efficient and automatic information flow.This research focuses on electronic data interchange (EDI), an important class of IT used for interorganizational information transfers in the supply chain. Data from a survey of the food industry is used to examine the use of EDI with respect to interfirm coordination activities involving suppliers and customers. The influence of demographic characteristics on EDI use is also investigated. The results suggest that firms view EDI as a tool for improving efficiencies rather than as a tool for facilitating supply chain integration. There is also a surprising difference in firms use of EDI with customers vis-à-vis suppliers. Firms tend to be much more accommodating of the desires of their customers than of their suppliers.

Time is an essential measure of performance in software development because time delays tend to fall directly to the bottom line. To address this issue, this research seeks to distinguish time-based software development practices: those managerial actions that result in faster development speed and higher productivity. This study is based upon a survey of software management practices in Western Europe and builds upon an earlier study we carried out in the United States and Japan. We measure the extent to which managers in the United States, Japan, and Europe differ in their management of software projects and also determine the tools, technology, and practices that separate fast and slow developers in Western Europe. Index Terms-Software engineering, software development, global performance comparisons, software speed and productivity, management factors, empirical research, Europe, Japan, and the United States. + 1.0. Blackburn and G.D. Scudder are with the Owen Graduate Recommended for acceptance by B. Littlewood. For information on obtaining reprints of this article, please send e-mail to: transse@computer.org, and reference IEEECS Log Number S95099. 0098-5589/96$05.00 0 1 996 IEEE Authorized licensed use limited to: The University of Arizona. Downloaded on January 9, 2009 at 12:25 from IEEE Xplore. Restrictions apply.