bluuebunny/crossref_metadata_2025 huggingface dataset:
HOSPITAL RESOURCE PLANNING: CONCEPTS, FEASIBILITY, AND FRAMEWORK
Authors: ROTH ALEDA V. , VANDIERDONCK ROLAND
Published: August 2010

The mantra of health care reform in hospitals in the United States and elsewhere, the spiralling costs of health care, and the development of diagnostic‐related groups (DRGS) that define health services as “products” are influencing the strategic role of operations planning and control in hospital delivery systems. We developed a new operations planning and control system that we call “Hospital Resource Planning” (HRP). This system is based on the concept of DRGS and the familiar concept of manufacturing resources planning (MRP‐II). TO determine the potential feasibility of HRP, we gathered longitudinal data from two hospitals, one 300‐bed community hospital and one 1,100‐bed teaching hospital. Our exploratory study indicated that while the concept of MRP‐II can be transferred to hospitals, the traditional MRP logic has shortcomings. HRP advances prior research in three ways: (1) consideration of DRGS as products with a bill of resources structure that simultaneously incorporates both capacity and materials resources, (2) implementation of a hospital‐wide (versus a functional) planning and control'system, and (3) gross‐to‐net requirements logic based on notions of treatment staging. Other feasibility issues that we addressed pertain to a stochastic bill of resources, trends toward hospital product standardization, and the coordination of a central planning system with decentralized decision making. The paper concludes with a description of areas for future research.
PRODUCTION SMOOTHING UNDER ENVIRONMENTAL CONSTRAINTS
Authors: HARTL RICHARD F.
Published: August 2010

This is an investigation into how optimal production rates and optimal price levels react to the introduction of an environmental tax on emissions. While, in the case of perfect competition, a linear tax has no effect, I show that in the monopolistic case the optimal production and emissions rates decrease in all instances‐without an additional smoothing effect. The desirable effect, emissions peaks being cut off, is only achieved when a progressive tax is imposed.
INDUSTRY STUDIES AND AMERICAN INDUSTRIAL PERFORMANCE
Authors: Lester Richard K.
Published: August 2010

A nationwide research program on the performance of American industry, sponsored by the Alfred P. Sloan Foundation, now involves scores of faculty researchers and more than 100 graduate students at several American universities. Ten research centers have been established, and each one is dedicated to the study of a particular industry. An eleventh center is carrying out research on problems that cut across these industries. It is expected that the Sloan Industry Studies program will make useful contributions to the performance of the industries themselves, to policymaking at all levels of government, and to the development of interdisciplinary research communities within the universities.
PRODUCT/PROCESS DESIGN IN MASS PLACEMENT PRINTED CIRCUIT BOARD ASSEMBLY
Authors: AHMADI JAVAD H. , AHMADI REZA H. , RAO JAY
Published: August 2010

We describe a set of models that are used to manage the product and process design in a mass placement printed circuit board (PCB) assembly cell. Our models can be divided into two categories. First, we characterize the cell design problem and develop models to design an efficient assembly cell. Second, we present models for optimizing the different operational aspects of the assembly cell. These models were developed to assist the managers of a large electronic manufacturing firm in establishing mass placement PCB assembly cells.
COMPETING THROUGH MANUFACTURING AND THE NEW MANUFACTURING PARADIGM: IS MANUFACTURING STRATEGY PASSE?
Authors: Clark Kim B.
Published: August 2010

In light of the widespread adoption of advanced production concepts over the last decade, the traditional concern of manufacturing strategy–linking manufacturing structure and infrastructure to business strategy–has seemed less powerful in explaining competitive success or improving competitive performance. Companies that have introduced just‐in‐time, total quality management, continuous improvement, design for manufacturability, or concurrent engineering appear to have reaped the benefits of quality, dependability, flexibility, high variety, and low cost. This raises an important question: is manufacturing strategy in its traditional vintage passe? In this paper, I first explore the logic behind the traditional prescriptions in manufacturing strategy using a classic case on Searle's Medical Instruments Group. Then, using the term advanced manufacturing system (AMS) as shorthand for best practice in production, design and engineering, and logistics, I revisit the Searle case as taught in 1995 to illustrate the logic of the AMS. Finally, I offer a framework for synthesis, arguing that manufacturing's true competitive power lies in integrating the capabilities of an AMS with strategic management of manufacturing.
A NOTE ON “COMMON DUE WINDOW SCHEDULING”
Authors: Weng Michael X. , Ventura Jose A.
Published: August 2010

Kramer and Lee recently addressed a common due window scheduling problem with earliness and tardiness penalties, where earliness and tardiness penalty factors are constant and the common window size is given. They showed that the problem is polynomial when the location of the due window is a decision variable. For the case where the location of the due window is given, the problem is also polynomial when the latest due date is greater than or equal to the makespan, and they proposed a pseudopolynomial dynamic programming algorithm to find an optimal schedule when the latest due date is less than the makespan. In this note we address the problem for the case where the location of the due window is given. Specifically, we show that the problem is polynomial if the window location is unrestricted, and present a more efficient dynamic program algorithm to optimally solve the problem if the window location is restricted. The concepts of unrestricted and restricted window locations are defined in this note.
AN EXPOSITION OF MULTIPLE CONSTRAINT SCHEDULING AS IMPLEMENTED IN THE GOAL SYSTEM (FORMERLY DISASTERTM)
Authors: Simons Jacob V. , Simpson Wendell P.
Published: August 2010

Since Eli Goldratt first appeared on the scene in the late 1970s, his ideas concerning production management have generated a huge amount of interest, controversy, and misunderstanding. These ideas have been proliferated under several names such as optimized production technology (OPT), drum‐buffer‐rope (DBR), synchronized manufacturing (SM), and theory of constraints (TOC). Although there seems to be general agreement on the importance of how capacity‐constrained resources are scheduled, research aimed at advancing the state of the art for the specific problem addressed by DBR continues to be limited by prior misunderstandings and the lack of a rigorous examination by the academic community. This paper seeks “to advance the state of research on constraint scheduling in several ways. First, it presents a concise history of the evolution of DBR. It then explains the use of rods in constraint scheduling. Next, it presents in detail the solution algorithm incorporated by the Goldratt Institute in their production software and, finally, relates that algorithm to alternative methods. In the process of these activities, several lingering misconceptions are resolved.
GLOBAL SUPPLY CHAINS: RESEARCH AND APPLICATIONS
Authors: COHEN MORRIS A. , MALLIK SUMAN
Published: August 2010

In this paper, we present a review of the models for the management of global supply chains and some evidence concerning current practice. Our review is restricted to the literature on intrafirm global supply chains and is motivated by empirical data concerning the extent of intrafirm globalization. The review of the literature suggests that research has not evolved in a coherent manner, while the data suggest that the extent of globalization is also hard to gauge. Indeed, the journey toward supply chain globalization is far from over. Significant gaps exist between theory and the practice. We conclude with a summary of directions for future research.
A COMPARISON OF RULES FOR ALLOCATING SETUP‐REDUCTION INVESTMENTS IN A CAPACITATED ENVIRONMENT
Authors: LESCHKE JOHN P. , WEISS ELLIOTT N.
Published: August 2010

This paper builds on a recent empirical study of the setup‐reduction process that suggests setup‐reduction proceeds through three major stages and that each stage is dominated by a particular type of investment function. Specifically, it examines the question of how to best prioritize investments during the stage that emphasizes standardizing setups across a work center.

We compare different investment‐allocation rules in a multi‐item, capacity‐constrained, dynamic demand environment under a variety of cost, demand, and investment assumptions. This analysis shows that significant differences in benefits can be achieved depending on the way setup‐reduction investments are prioritized.
THE PERILS OF EXCELLENCE: BARRIERS TO EFFECTIVE PROCESS IMPROVEMENT IN PRODUCT‐DRIVEN FIRMS
Authors: HENDERSON REBECCA , DELALAMO JESUS , BECKER TODD , LAWTON JAMES , MORAN PETER , SHAPIRO SAUL
Published: August 2010

Several authors have suggested that a focus on manufacturing capability and on continued process improvement may be a powerful source of competitive advantage, yet many firms appear to have encountered great difficulties in taking advantage of this insight. This paper reports on the results of five these conducted under the auspices of the MIT Leaders for Manufacturing program at the Microwave Technology Division of the Hewlett‐Packard Company. We found considerable evidence that the marginal returns to process development within the division were probably considerably higher than the division's cost of capital, suggesting that process improvement probably was underfunded despite the fact that improving manufacturing capability had been identified as a key strategic priority.

We found no evidence that this “underfunding” reflected either a failure to recognize the problem or an overly hierarchical or rigid organization. Rather it appeared to flow from the historical strengths of the division. A devotion to leading‐edge technical solutions and to immediate customer service at almost any price had created barriers to the effective funding of process improvement that were deeply rooted in the organizational structures, information systems, and formal and informal incentive structures that had evolved to support the division's historical emphasis on excellence on product design. Our results highlight the problems that very successful product‐driven companies may encounter in attempting to make continual process improvement central to their strategic mission.
AN INTEGRATIVE APPROACH TO PROCESS PARAMETER SELECTION
Authors: MACDONALD FRANCIS , ROSENFIELD DONALD B. , STAELIN DAVID H. , KNAUSS KEITH
Published: August 2010

This case study of a process improvement project from the Hewlett‐Packard Analytic Products Group illustrates a number of important approaches for operations strategy. First, we show how process control in capillary tube manufacturing led to a significant improvement in tubing strength, a quality measure that relates to the frequency of tube defects at a particular stress level. Next, we show how one particular approach used for experimental design and process improvement was considerably more economical than another standard method. In conclusion, we link the process characteristics such as defect frequency to strategic measures such as company revenue and investment to underscore the strategic importance of process control.
A THREE‐PHASE APPROACH TO INSTILLING A CONTINUOUS LEARNING CULTURE IN MANUFACTURING EDUCATION AND TRAINING
Authors: MOSKOWITZ HERBERT , WARD JAMES
Published: August 2010

We describe a “learn‐by‐doing” approach that involves the following three phases designed in part to integrate management and engineering curricula and instill a continuous learning philosophy: (1) involve cross‐functional teams as “process and business owners” in a replica of a real‐life manufacturing/design problem (Do), (2) require teams to not only learn by doing but to then apply or implement what they have learned in phase 1 (Apply), and (3) share best practices and knowledge gained with subsequent participants (Document). These last two phases are essential and potentially the most valuable but are often ignored in the learning process. They can be accomplished either manually or through the use of an electronic bookshelf (e.g., company or school intranet), which is a database system used to collect and store templates of best practices, collective wisdom, and related information associated with learning and operational activities. We describe two of several educational packages we have developed and discuss their impact on our teaching, our students, and practitioners.
IMPROVING POM LEARNING: SYSTEMS THINKING AND TRANSPARENT‐BOX BUSINESS SIMULATORS
Authors: MACHUCA JOSé A. D.
Published: August 2010

It is well known by systems thinkers that the behavior of complex systems (for example, the company as a whole or the operations subsystem) depends upon their structure (the set of system variables and their interrelationships). In our opinion, the methods and tools presently used for production and operations management (pom) teaching are insufficient to cope with an ever more complex reality. Over the last few years, the research group GIdEao, following an original idea (Machuca 1992a, 1992b) has been developing transparent‐box business simulators (TBBSS) based on systems thinking and system dynamics models; the aim was to maintain the advantages of the existing didactic tools while mitigating their drawbacks. The most distinctive feature of TBBSS (as opposed to the traditional black‐box business games) is that the structure of the system to be simulated is always accessible to the users, who can thus reflect on the causes underlying the results obtained and thereby improve decision‐making and the learning process. We will show how to work with TBBSS, and we will comment on the results obtained in an empirical experiment which aims to measure the influence of TBBSS on the learning process.
COMPUTER INTEGRATION AND CATASTROPHIC PROCESS FAILURE IN FLEXIBLE PRODUCTION: AN EMPIRICAL INVESTIGATION
Authors: UPTON DAVID M. , MCAFEE ANDREW P.
Published: August 2010

This paper empirically investigates the effect of advanced manufacturing technology on process stability during flexible production in a process industry. A sample of 61 North American fine paper plants is used to examine the relationship between the level of automation installed for controlling changes between paper grades and the incidence of paper web breaks. These web breaks are catastrophic failures; they require the entire plant to be stopped, reinitialized, and restarted. Because a large fraction of breaks occurs shortly after changeovers, they are an important determinant of the aspect of plant flexibility, called mobility, or the ability to move between products with only small penalties.

In an attempt to ensure stable and mobile production, many plants have implemented changeover automation. We find, however, that higher levels of this automation are significantly associated with higher rates of catastrophic failure among the plants studied. We suggest that this finding becomes less paradoxical when considered in light of a recent stream of research on advanced manufacturing technologies, loosely called the usability perspective. According to this perspective, automation designed and implemented with the narrow, technical goal of replacing human operators or removing their discretion over a production process is misguided, especially in environments in which requirements are changing rapidly.
OPTIMAL BUFFER ALLOCATION IN ASYNCHRONOUS CYCLIC MIXED‐MODEL ASSEMBLY LINES
Authors: FUXMAN LEONORA
Published: August 2010

This paper considers a problem of optimal buffer allocation in cyclic asynchronous mixedmodel assembly lines with deterministic processing times. An analytical model is used to provide new insights into properties of optimal buffer allocation, that is, a buffer configuration that guarantees the highest possible throughput rate on the assembly line with a minimum number of buffers. Optimal buffer configuration is characterized, and an efficient algorithm to find such a configuration is developed. The approach proposed in this paper also provides insights on how to allocate a given number of buffers to workstations on the assembly line to maximize the throughput rate.
RESOURCE ALLOCATION TO IMPROVE SERVICE QUALITY PERCEPTIONS IN MULTISTAGE SERVICE SYSTEMS
Authors: Soteriou Andreas C. , Hadjinicola George C.
Published: August 2010

Service quality improvement has become an imperative in today's service firms. In this paper, we present a modeling framework that combines marketing and operations viewpoints for resource allocation. The framework can be used to allocate resources to the different stages of a multistage service system, where the manager's goal is to improve customers' perceptions of service quality, given some budget. Optimal allocation guidelines are provided, and the interplay of three factors on the resulting allocation scheme is captured. These factors are the current level of customers' perceptions of service quality at each stage, the cost of implementing a service quality improvement at each stage, and the importance placed by customers at each stage. Sensitivity analysis to provide additional managerial insights is also performed. We demonstrate the applicability of the modeling framework, using data from a real life health care environment. Model limitations and future research are also discussed.
MEASUREMENT OF MULTIPLE SITES IN SERVICE FIRMS WITH DATA ENVELOPMENT ANALYSIS
Authors: Metters Richard D. , Frei Frances X. , Vargas Vicente A.
Published: August 2010

Data envelopment analysis (dea) has become an increasingly popular method to measure performance for service firms with multiple sites. DEA is superior to many traditional methods for firms that have multiple goals. The promise of DEA is that the complex, multi‐objective problem of performance measurement can be reduced to a single number. Unfortunately, the practice of DEA often belies the promise. Misconceptions concerning the purpose and implementation of DEA can cause DEA applications to be less than successful. Here, the technique is explained, and a guide to the implementation of DEA is proposed, utilizing DEA studies of retail bank branches.
PERFORMANCE ANALYSIS OF AN ASSEMBLY STATION WITH INPUT FROM MULTIPLE FABRICATION LINES
Authors: RAO P. CHANDRASEKHAR , SURI RAJAN
Published: August 2010

We develop analytical models for performance evaluation of Fabrication/Assembly (F/A) systems. We consider an F/A system that consists of an assembly station with input from K fabrication lines. Each fabrication line consists of one or more fabrication stations. The system is closed with a fixed number of items circulating between each fabrication line and the assembly station. We present algorithms to estimate the throughput and mean queue lengths of such systems with exponential processing times. We then extend our approach to analyze F/A systems with general processing time distributions. Numerical comparisons with simulations demonstrate the accuracy of our approach.
TEACHING SUPPLY CHAIN MANAGEMENT TO BUSINESS EXECUTIVES
Authors: Vollmann Thomas E. , Cordon Carlos , Heikkila Jussi
Published: August 2010

By focusing on the management of entire value chains, supply chain management has gained increasing popularity in management research and in the teaching of global businesses. The right practices can take companies to great heights; lack of attention can draw companies close to peril. In teaching supply chain management to business executives, there are four major issues that need to be highlighted: flawless execution of operations, the change from supply to demand focus, outsourcing and supply base development, and partnership implementation. This article explains these four issues, and the material that is developed at IMD to teach each of them.
MULTIPLE RATERS IN SURVEY‐BASED OPERATIONS MANAGEMENT RESEARCH: A REVIEW AND TUTORIAL
Authors: Boyer Kenneth K. , Verma Rohit
Published: August 2010

Research in the area of operations strategy has made significant progress during the past decade in terms of quantity of articles published, as well as the quality of these articles. Recent studies have examined the published literature base and determined that, in general, the field has progressed beyond an exploratory stage to a point where there is a core set of basic terminology and models. Concurrent with the formation and solidification of a core terminology, there is an increasing emphasis on developing and employing a set of reliable, valid, and reproducible methods for conducting research on operations strategy.

We provide a review of common methods for assessing the degree of reliability and agreement of the responses provided by multiple raters within a given organization to a set of qualitative questions. In particular, we examine four methods of determining whether there is evidence of disagreement or bias between multiple raters within a single organization in a mail survey.
AN EVALUATION OF ORDER PICKING POLICIES FOR MAIL ORDER COMPANIES
Authors: PETERSEN CHARLES G.
Published: August 2010

This paper is concerned with the problem of order picking in mail order companies. Order picking is the retrieval of items from their warehouse storage locations to satisfy customer orders. Five order picking policies, strict order, batch, sequential zone, batch zone, and wave, are evaluated using labor requirements, processing time, and customer service as performance measures. A simulation model was developed to investigate these picking policies in a mail order environment. Prior research has focused on the study of individual picking policies. This study extends the prior research by evaluating multiple picking policies under varying operating conditions. The results of the study seem to indicate that (1) wave picking and batch picking perform well across the range of operating conditions considered in this study, and (2) sequential zone and batch zone picking do not perform well, especially as the order volume increases. However, the benefits and drawbacks to each picking policy must be taken into account. The key to effective implementation of an order picking system is to match the firm's business strategy, capabilities, technology, and space requirements with an order picking policy that maximizes the benefits of order picking to the firm and its customers.
LOT‐SIZING IN CAPACITATED MULTI‐STAGE SERIAL SYSTEMS
Authors: ARMENTANO VINÍCIUS A. , BERRETTA REGINA ESTHER , FRANCA PAULO M.
Published: August 2010

The lot‐sizing problem in capacitated multi‐stage systems with a serial product structure is addressed. This is a complex optimization problem that is part of the decision set in material requirements planning (MRP) systems. The mathematical model that describes the problem uses the concept of echelon stock and includes lead times. Setup times are taken into account, which implies that the problem of finding a feasible solution is NP‐Complete. This paper proposes a heuristic method that provides a production plan in order to minimize inventory, production, and setup costs. The heuristic starts from a solution for the uncapacitated problem, which is given by the sequential application of the Wagner‐Whitin algorithm. Feasibility is then attempted by shifting production amounts between periods. Computational tests conducted in 1,800 instances with up to 40 components and 18 periods have shown that feasible solutions were obtained in 83.7% of the instances. For the infeasible instances, on average, the heuristic is able to find solutions with very low capacity excess. The solutions' quality is evaluated through a lower bound provided by Lagrangean relaxation and on average the gap is less than 10%.
LOOKING AHEAD BY LOOKING BACK: SWIFT, EVEN FLOW IN THE HISTORY OF MANUFACTURING
Authors: SCHMENNER ROGER W.
Published: August 2010

Manufacturing history is too often neglected in operations management and its lessons lost. Its usefulness for testing theory is under‐appreciated. This paper uses critical aspects of the history of manufacturing to provide support for the Theory of Swift, Even Flow as an explanation of productivity gain. The rise of Britain in the Industrial Revolution and the rapid overtaking of Britain by the United States and Germany are argued to be thoroughly consistent with Swift, Even Flow, thereby vindicating both theory and the usefulness of history.
QUALITY MANAGEMENT: UNIVERSAL OR CONTEXT DEPENDENT?
Authors: SOUSA RUI , VOSS CHRISTOPHER A.
Published: August 2010

Quality management has often been advocated as being universally applicable to organizations. This is in contrast with the manufacturing strategy contingency approach of Operations Management that advocates internal and external consistency between manufacturing strategy choices. This article empirically investigates whether quality management practices are contingent on a plant's manufacturing strategy context, by examining the use of process quality management practices—a critical and distinctive subset of the whole set of quality management practices—across plants representative of different manufacturing strategy contexts. The study strongly suggests that process quality management practices are contingent on a plant's manufacturing strategy, and identifies mechanisms by which this takes place.
QUALITY AND WORK FORCE MANAGEMENT PRACTICES: THE MANAGERIAL PERFORMANCE IMPLICATION
Authors: KATHURIA RAVI , DAVIS ELIZABETH B.
Published: August 2010

Quality has been in the limelight as organizations have sought to create a competitive advantage and theorists have sought to understand the implications of quality management. This paper examines the synergistic effects of the quality emphasis in the organizations, the use of appropriate work force management practices, and the managerial performance outcomes as interactive phenomena. Using data from multiple levels of employees in manufacturing units in various industries, we tested hypotheses regarding the managerial performance impact of the synergy in work force management practices and the quality emphasis. The results indicate that the effectiveness of work force management practices in enhancing managerial performance varies with the emphasis on quality that is manifested by meeting and exceeding customer needs and preferences through accurate, consistent, reliable, and durable products, and by making design changes in the products as desired by the customer.
STRATEGIC ASPECTS OF QUALITY: A THEORETICAL ANALYSIS
Authors: NARASIMHAN RAM , MÉNDEZ DAVID
Published: August 2010

This paper investigates the relationship between aspects of quality and long run profitability and growth of a firm. The paper first determines whether a stable relationship among price, aspects of quality, and the sales rate exists, by examining the equilibrium properties of a dynamic model. Then, we use the derived equilibrium expressions to develop insights into the strategic nature of “quality reputation” and, how to integrate marketing (i.e., pricing) and quality related decisions. The paper shows under certain conditions it might be more advantageous to manipulate “quality reputation” through advertising and product innovations than to increase product quality. We comment on quality based strategic options a firm must consider to ensure long run growth and profitability.
SERVICE PROCESS CONFIGURATIONS IN ELECTRONIC RETAILING: A TAXONOMIC ANALYSIS OF ELECTRONIC FOOD RETAILERS
Authors: HEIM GREGORY R. , SINHA KINGSHUK K.
Published: August 2010

We developed a taxonomy of service processes in electronic retailing using data from 255 electronic food retailers. The taxonomy is comprised of eight service process configurations. Analysis of publicly available data on on‐line customer ratings for 52 retailers in the study sample shows that the ordering of the configurations in the taxonomy on a continuum of low to high flexibility is associated positively with (i) customer satisfaction with web site aesthetics, web site navigation, product selection, product information, customer support, and ease of return, and (ii) customer loyalty.
THE EFFECT OF LEARNING ON THE MAKE/BUY DECISION
Authors: ANDERSON EDWARD G. , PARKER GEOFFREY G.
Published: August 2010

By including the effects of learning over time on both the production of components and their integration into complete products, we develop an engineering‐based model of outsourcing. This model provides an alternative explanation for much of what other outsourcing theories predict, as well as making several new predictions. In particular, we show that outsourcing decisions can create a path‐dependent outsourcing trap in which a firm experiences higher long‐run costs after an immediate cost benefit. We also describe conditions under which outsourcing a small fraction of component production may dominate either complete insourcing or complete outsourcing. Finally, we show that, with discounting, there is a convex, curvilinear relationship between the optimal outsourcing fraction and the rate of technological change.
A SIMPLE HEURISTIC FOR DYNAMIC ORDER SIZING AND SUPPLIER SELECTION WITH TIME‐VARYING DATA
Authors: TEMPELMEIER HORST
Published: August 2010

In this paper we consider the problem of supplier selection and purchase order sizing for a single item under dynamic demand conditions. Suppliers offer all‐units and/or incremental quantity discounts, which may vary over time. Although the problem refers to a typical planning task of a purchasing agent, which is often solved without algorithmic assistance, in an eBusiness (b2b) environment, the need for the integration of an automatic performance of this planning task into a web‐based procurement process becomes evident. A new model formulation for this problem is developed, and a simple but easily extendible heuristic procedure is presented and tested. The heuristic is implemented as part of the Advanced Planner and Optimizer (apo) software of SAP AG, Walldorf, Germany.
EFFECTIVENESS OF STOCK TRANSSHIPMENT UNDER VARIOUS DEMAND DISTRIBUTIONS AND NONNEGLIGIBLE TRANSSHIPMENT TIMES*
Authors: TAGARAS GEORGE , VLACHOS DIMITRIOS
Published: August 2010

This paper investigates the operational characteristics of a pooling group consisting of two stocking locations, supplied periodically by a central warehouse. The two locations may collaborate by moving inventory between them. The lateral transshipment times are shorter than the regular replenishment lead times, but they are not negligible. Several alternative types of ordering and transshipment policies are examined. Extensive experimentation by simulation leads to the conclusion that the benefits of risk pooling are substantial only when demand is highly variable. Moreover, the type and variability of the demand distributions are key determinants of the appropriate transshipment policy and pooling groups design.
SCHEDULING HYBRID FLOWSHOPS IN PRINTED CIRCUIT BOARD ASSEMBLY LINES*
Authors: JIN Z. H. , OHNO K. , ITO T. , ELMAGHRABY S. E.
Published: August 2010

We treat a three‐stage hybrid flowshop for the production of printed circuit boards (PCB), suggested to us by a real‐life production situation. The problem is to determine a schedule that minimizes the makespan for a given demand profile over a finite planning horizon. We propose a global procedure that utilizes genetic algorithms and three subproblems. The performance of the procedure is evaluated via experimentation over thousands of problem realizations that are randomly generated. The experimental results show the efficiency of the global procedure and provides qualitative answers to the allocation of machines to the various stages.
THE VALUE OF SKU RATIONALIZATION IN PRACTICE (THE POOLING EFFECT UNDER SUBOPTIMAL INVENTORY POLICIES AND NONNORMAL DEMAND)
Authors: ALFARO JOSÉ A. , CORBETT CHARLES J.
Published: August 2010

Several approaches to the widely recognized challenge of managing product variety rely on the pooling effect. Pooling can be accomplished through the reduction of the number of products or stock‐keeping units (SKUs), through postponement of differentiation, or in other ways. These approaches are well known and becoming widely applied in practice. However, theoretical analyses of the pooling effect assume an optimal inventory policy before pooling and after pooling, and, in most cases, that demand is normally distributed. In this article, we address the effect of nonoptimal inventory policies and the effect of nonnormally distributed demand on the value of pooling. First, we show that there is always a range of current inventory levels within which pooling is better and beyond which optimizing inventory policy is better. We also find that the value of pooling may be negative when the inventory policy in use is suboptimal. Second, we use extensive Monte Carlo simulation to examine the value of pooling for nonnormal demand distributions. We find that the value of pooling varies relatively little across the distributions we used, but that it varies considerably with the concentration of uncertainty. We also find that the ranges within which pooling is preferred over optimizing inventory policy generally are quite wide but vary considerably across distributions. Together, this indicates that the value of pooling under an optimal inventory policy is robust across distributions, but that its sensitivity to suboptimal policies is not. Third, we use a set of real (and highly erratic) demand data to analyze the benefits of pooling under optimal and suboptimal policies and nonnormal demand with a high number of SKUs. With our specific but highly nonnormal demand data, we find that pooling is beneficial and robust to suboptimal policies. Altogether, this study provides deeper theoretical, numerical, and empirical understanding of the value of pooling.
ANALYSIS OF THE LEAD TIME AND LEARNING FOR CAPACITY EXPANSIONS
Authors: GAIMON CHERYL , BURGESS ROBERT H.
Published: August 2010

Firms capable of reducing the time required to bring new products to the marketplace realize significant competitive gains. In this context, the existing literature on capacity expansion is limited because it does not consider the lead time required to construct and operationalize new capacity. Models are introduced here that capture the capacity expansion lead time as well as two types of learning. Specifically, learning may reduce the lead time or cost required to complete an expansion. Analytic and numerical results show that the optimal solution can be significantly affected by the explicit treatment of the lead time and learning.
HAZARDOUS WASTE DISPOSAL: A WASTE‐FUEL BLENDING APPROACH
Authors: FLOWERS A. DALE , LINDERMAN KEVIN
Published: August 2010

The disposal of hazardous wastes creates major economic and environmental problems. One productive use of hazardous wastes is to blend them into fuel, which mitigates damage to the environment by recycling waste into fuel and reducing fossil‐fuel consumption. Operations personnel face a daunting task of efficiently blending hazardous waste into fuel, while simultaneously maintaining environmental regulatory requirements. This research develops a goal‐programming approach to the waste‐fuel‐blending process that considers the diverse objectives of fuel managers. A realworld case study at a cement kiln illustrates the effectiveness of this approach, where the implementation followed principles of team building and quality management.
EFFECTS OF ENVIRONMENTAL MANAGEMENT SYSTEMS ON ENVIRONMENTAL MANAGEMENT PRACTICES AND OPERATIONS
Authors: SROUFE ROBERT
Published: August 2010

To date, it is unclear as to how Environmental Management Systems (EMS) are implemented and what effects these systems have on other environmental and operational practices. This study reports empirical insights to EMS practices based on the largest EMS survey of manufacturing firms in the United States. The objective of the study is to test for a relationship between environmental management systems and perceived operations performance while considering direct and indirect effects of various environmental practices. The results of this study are supported by several field studies and provide a new source of information regarding EMS theory development. The results also indicate a positive relationship between an EMS, the environmental practices a firm engages, and operations performance measures.
OPTIMAL PROJECT SEQUENCING WITH RECOURSE AT A SCARCE RESOURCE
Authors: KAVADIAS STYLIANOS , LOCH CHRISTOPH H.
Published: August 2010

We develop a dynamic prioritization policy to optimally allocate a scarce resource among K projects, only one of which can be worked on at a time. When the projects' delay costs differ, the problem (a “restless bandit”) has not been solved in general. We consider the policy of working on the project with the highest expected delay loss as if the other project was completely finished first (although recourse is allowed). This policy is optimal if: (1) the delay cost increases with the delay regardless of the performance state, (2) costs are not discounted (or, discounting is dominated by delay costs), (3) projects are not abandoned based on their performance state during processing at the scarce resource, and (4) there are no stochastic delays. These assumptions are often fulfilled for processing at specialized resources, such as tests or one‐off analyses.
Planning and Scheduling in Supply Chains: An Overview of Issues in Practice
Authors: Kreipl Stephan , Pinedo Michael
Published: August 2010

This paper gives an overview of the theory and practice of planning and scheduling in supply chains. It first gives an overview of the various planning and scheduling models that have been studied in the literature, including lot sizing models and machine scheduling models. It subsequently categorizes the various industrial sectors in which planning and scheduling in the supply chains are important; these industries include continuous manufacturing as well as discrete manufacturing. We then describe how planning and scheduling models can be used in the design and the development of decision support systems for planning and scheduling in supply chains and discuss in detail the implementation of such a system at the Carlsberg A/S beerbrewer in Denmark. We conclude with a discussion on the current trends in the design and the implementation of planning and scheduling systems in practice.
Real‐Time Work Schedule Adjustment Decisions: An Investigation and Evaluation
Authors: Hur Daesik , Mabert Vincent A. , Bretthauer Kurt M.
Published: August 2010

Service managers often find that available worker capacity does not match with actual demand during a given day. They then must attempt to modify the planned work schedule to improve service and increase profitability. This study, which defines such a setting as the real‐time work schedule adjustment decision, proposes mathematical formulations of the real‐time adjustment and develops efficient heuristic approaches for this decision. The study evaluates the relative effectiveness of these heuristics versus experienced service managers, investigates the effect of the degree of schedule adjustment on profitability, and assesses the effect of demand forecast update errors on the performance of the schedule adjustment efforts. First, the results indicate that the computer based heuristics achieve higher profit improvement than experienced managers. Second, there is a trade‐off between schedule stability and profitability so that more extensive schedule revisions (efficiency first heuristics) generally result in higher profitability. However, the incremental return on schedule changes is diminishing. Third, we find that active adjustments of work schedules are beneficial as long as the direction of demand change is accurately identified.
Dynamic Policies for Optimal LEO Satellite Launches
Authors: Gavish Bezalel , Kalvenes Joakim
Published: August 2010

Low‐earth orbit satellite (LEO) systems continue to provide mobile communication services. The issue of cost containment in system maintenance is a critical factor for continued operation. Satellite finite life‐times follow a stochastic process, and since satellite replenishment cost is the most significant on‐going cost of operation, finding optimal launch policies is of paramount importance. This paper formulates the satellite launch problem as a Markovian decision model that can be solved using dynamic programming. The policy space of the system is enormous and traditional action space dominance rules do not apply. In order to solve the dynamic program for realistic problem sizes, a novel procedure for limiting the state space considered in the dynamic program is developed. The viability of the proposed solution procedure is demonstrated in example problems using realistic system data. The policies derived by the proposed solution procedure are superior to those currently considered by LEO system operators, and result in substantial annual cost savings.
Revisiting ISO 14000 Diffusion: A New “Look” at the Drivers of Certification
Authors: Vastag Gyula
Published: August 2010

This replication study of the drivers of ISO 14000 certifications extends the work of Corbett and Kirsch (2001) and provides a different and simpler predictive model of the factors contributing to the growth of ISO 14000 certifications. The main finding is that at national level ISO 14000 certification densities can be explained by two factors: the installed base of ISO 9000 certificates and the number of environmental treaties signed and ratified. The first factor, considering the common elements of the two standards, points to conditions of infrastructural convenience, while the second highlights the importance of political‐economic considerations. The study uses a new set of tools (graphical displays, distribution‐free computer intensive methods) that are better suited for exploratory research when discontinuities and existence of subgroups in the data set may make findings from a linear regression suspect.
Why Does Cell Implementation Stop? Factors Influencing Cell Penetration in Manufacturing Plants
Authors: Johnson Danny J. , Wemmerlöv Urban
Published: August 2010

There is little understanding as to why firms have various degrees of cell usage. The intent of this study was to identify factors that had arrested continued implementation of cells at surveyed manufacturing plants. We found no dominant factor that had prevented the firms from continued cellularization. However, by sub‐dividing the plants into those with low and high degrees of direct labor hours spent in cells, short and long experience with cells, and those with and without plans for further cells, a clearer pattern emerged. The inability to find families with high and stable demand, lack of time to implement more cells, the existence of service processes, and the difficulty of cost justifying new cells were the most important factors, although their relative importance varied. The findings support the notion that cellular manufacturing has broad applicability as a form of work organization and that cell users pursue further implementations until no more viable cells with sufficient utilization, demand stability, or economic value can be found.
Supplier Selection via Tournaments
Authors: Deng Shi‐Jie , Elmaghraby Wedad
Published: August 2010

In this paper, we study the performance of a sourcing mechanism gaining popularity in industrial procurement environments; a tournament. Under a tournament, a buyer initially procures her parts from two suppliers with possibly different quality levels, for T time periods, i.e., she parallel sources. During this time, the buyer is able to observe noisy signals about the suppliers' quality. At time T, she selects the supplier with the highest observed performance and awards it the remainder of her business. We characterize the optimal duration of the tournament as a function of various market parameters, including information and investment costs. Furthermore, we demonstrate that a tournament can be more profitable for the buyer than selecting the highest quality supplier at time T = 0 and sole sourcing entirely.
Axiomatic Based Decomposition for Conceptual Product Design
Authors: Mullens Michael A. , Arif Mohammed , Armacost Robert L. , Gawlik Thomas A. , Hoekstra Robert L.
Published: August 2010

This paper describes a structured methodology for decomposing the conceptual design problem in order to facilitate the design process and result in improved conceptual designs that better satisfy the original customer requirements. The axiomatic decomposition for conceptual design method combines Alexander's network partitioning formulation of the design problem with Suh's Independence Axiom. The axiomatic decomposition method uses a cross‐domain approach in a House of Quality context to estimate the interactions among the functional requirements that are derived from a qualitative assessment of customer requirements. These interactions are used in several objective functions that serve as criteria for decomposing the design network. A new network partitioning algorithm is effective in creating partitions that maximize the within‐partition interactions and minimize the between‐partition interactions with appropriate weightings. The viability, usability, and value of the axiomatic decomposition method were examined through analytic comparisons and qualitative assessments of its application. The new method was examined using students in engineering design capstone courses and it was found to be useable and did produce better product designs that met the customer requirements. The student‐based assessment revealed that the process would be more effective with individuals having design experience. In a subsequent assessment with practicing industrial designers, it was found that the new method did facilitate the development of better designs. An important observation was the need for limits on partition size (maximum of four functional requirements.) Another issue identified for future research was the need for a means to identify the appropriate starting partition for initiating the design.
Project Scheduling—Theory and Practice
Authors: Herroelen Willy
Published: August 2010

The project scheduling problem involves the scheduling of project activities subject to precedence and/or resource constraints. Of obvious practical importance, it has been the subject of intensive research since the late fifties. A wide variety of commercialized project management software packages have been put to practical use. Despite all these efforts, numerous reports reveal that many projects escalate in time and budget and that many project scheduling procedures have not yet found their way to practical use. The objective of this paper is to confront project scheduling theory with project scheduling practice. We provide a generic hierarchical project planning and control framework that serves to position the various project planning procedures and discuss important research opportunities, the exploration of which may help to close the theory‐practice gap.
Erratum: A Model of Site‐Specific Antecedents of ISO 14001 Certification
Authors: Melnyk Steven A. , Sroufe Robert P. , Calantone Roger J. , Montabon Frank
Published: August 2010

This erratum is to correct the authorship of the article by Melnyk, Sroufe, and Calantone (2003). Frank Montabon is also one of the co‐authors of the article, and his name was inadvertently omitted from the list of authors. He should be listed as a co‐author of the article.