Cost and Shortage Trade-Offs in Aggregate Production Planning*

It is exceedingly difficult, if not impossible, to measure shortage costs. To bypass this difficulty in aggregate production planning, this paper develops an optimal policy function (piecewise linear or a curve) for trade-offs between shortages and the sum of production and inventory costs. The optimal management decision is based on this function. It should be of major interest in production planning since similar functions for inventory management have been successfully applied in practice.     

Multi-objective simulation optimization using data envelopment analysis and genetic algorithm: Specific application to determining optimal resource levels in surgical services

Simulation is a powerful tool for modeling complex systems with intricate relationships between various entities and resources. Simulation optimization refers to methods that search the design space (i.e., the set of all feasible system configurations) to find a system configuration (also called a design point) that gives the best performance. Since simulation is often time consuming, sampling as few design points from the design space as possible is desired. However, in the case of multiple objectives, traditional simulation optimization methods are ineffective to uncover the efficient frontier. We propose a framework for multi-objective simulation optimization that combines the power of genetic algorithm (GA), which can effectively search very large design spaces, with data envelopment analysis (DEA) used to evaluate the simulation results and guide the search process. In our framework, we use a design point's relative efficiency score from DEA as its fitness value in the selection operation of GA. We apply our algorithm to determine optimal resource levels in surgical services. Our numerical experiments show that our algorithm effectively furthers the frontier and identifies efficient design points.     

Optimal Design of a Two-Level Transportation Network with a Different Unit Cost for Each Secondary Link*

The objective of this paper is to further develop Singhal's (1990) framework for designing a two-level hierarchical transportation network consisting of a trunk or primary link and several feeder or secondary links. Secondary links are perpendicular lines from each of the given points and the primary link is a straight line or curve connecting the feet of two extreme perpendicular lines. The problem and the associated strategic and operational considerations such as cost, time, feasibility, and preferred regions for the primary link in the context of rural highway planning are discussed. Two-level networks are also common in electricity transmission, pipelines, and telecommunication design. The core of the framework is a model for finding the path of a primary link such that a weighted sum of the lengths of the perpendicular lines from each point to a linear primary link and the distance between the feet of the two extreme perpendicular lines is minimized. The analysis shows that for almost every problem there exists a wide range of solutions for which the total cost is only slightly higher than that of the optimal solution. This offers considerable flexibility to the decision maker. These solutions can be evaluated in view of the broader objectives and constraints that are not included in the model. The use of computer graphics and the option of a nonlinear or piecewise linear primary link are also discussed.     

INTERNATIONAL TECHNOLOGY AND OPERATIONS MANAGEMENT: RESOURCE TOOLKIT FOR RESEARCH AND TEACHING

Increasing globalization has affected the way that firms are managed today. While its impact on competitive strategy, marketing, and finance has been well accepted and well studied, its effect on the firm's technology and operations has not. This paper provides resources for research and teaching in international technology and operations management (itom). Included are an extensive bibliography of papers and an overview of large-scale survey research initiatives in the area. By bringing together and categorizing this body of work, we hope to facilitate further work in the area and to help define ITOM'S scope.     

The Effects of Knowledge Management on Team Members' Ratings of Project Success and Impact*

Many organizations are trying to improve the generation and utilization of knowledge. The activities associated with these efforts are identified as organizational knowledge management (KM). While much has been written about knowledge management from the organizational level, the success of such efforts over the long run will depend upon on how KM activities impact important outcomes as perceived by those at the employee level who actually implement the activities. This study used the input‐process‐output framework of team effectiveness to investigate the relationship between selected KM‐related activities on integrated product and process development team members' satisfaction with their project's success and the impact they expected it to have on the organization. The results indicate that team‐level leadership and support (i.e., inputs), along with knowledge generation and dissemination (i.e., processes), are key drivers of member performance‐related ratings (i.e., outputs). Finally, and possibly most importantly, a number of interactions were evident suggesting that the KM processes moderate the effects of the KM inputs. These findings and their implications are discussed.