A DECISION THEORY APPROACH TO PRIORITY DISPATCHING FOR JOB SHOP SCHEDULING

Recent developments in the design of job shop scheduling systems have inspired a new approach to priority dispatching. The basis for the approach is in elementary decision theory: at each decision juncture define the alternative courses of action, evaluate the consequences of each alternative according to a given criterion, and choose the best alternative. The experimental results of a simulated single machine queueing system reinforce earlier findings that a decision theory approach represents a significant advance over conventional priority dispatching.     

EVALUATING ORDER RELEASE MECHANISMS IN A JOB SHOP WITH SEQUENCE-DEPENDENT SETUP TIMES

Job-release mechanisms in job-shop control are receiving increased recognition in recent research. However, there is considerable disagreement over the benefits of sophisticated job-release mechanisms, and they remain to be tested in various operating environments. In our study, we extend previous job-releasing research by examining several job-release mechanisms in a different operating environment-a sequence-dependent setup job shop. We tested these release mechanisms, originally developed for a machine-constrained job shop, in conjunction with two groups of sequencing rules-ordinary and setup-oriented sequencing rules. We measured shop performance in terms of total cost, the sum of inventory-holding and late-penalty costs. We developed a simulation model of a nine-machine job shop for our experiment.     

THE IMPACT OF LOCAL CONTENT RULES ON GLOBAL SOURCING DECISIONS

Many governments have established, for various reasons, local confent purchasing rules for companies that wish to operate in their country. These requirements force firms to purchase a certain amount of components from suppliers located in that country. This paper describes local content rules and develops models to select suppliers while satisfying local content provisions. The single plant model can be transformed into a knapsack problem that is solved by a ranking procedure, and the solution provides insight as to the manner in which local content rules impact more generalized models. Furthermore, we illustrate possible negative effects to local industry that may result when governments set the local content percentage too high, and we discuss methods for companies to circumvent local content rules. Finally, we address the issue of local content rules in the context of multi-plant global sourcing decisions, and we provide an efficient solution procedure for the classical plant location model extended to include local content rules at each site     

THE IMPACT OF ELECTRONIC DATA INTERCHANGE ON DELIVERY PERFORMANCE

After several years of use of electronic data interchange (EDI) in various industries, the literature is still inconclusive regarding the benefits gained from its usage. We investigated contextual factors of two types: non‐managerial (product diversity, product customization, production instability, and organizational size) and managerial (just‐in‐time and quality management), that might have confounded past results. Our results indicate that the extent of EDI use is significantly related to delivery performance after controlling for the above‐mentioned factors. Furthermore, the data set supported the moderating effect of production instability on the relationship between the extent of EDI use and delivery performance achieved, but failed to support the moderating effect of organizational size.     

THE PERFORMANCE OF A SIMPLE INCREMENTAL LOT-SIZING RULE IN A MULTILEVEL INVENTORY ENVIRONMENT

A simple incremental cost approach to lot sizing was tested in a multilevel inventory environment. The incremental approach has not previously been tested in a large-scale study involving multiple product-structure levels. Using the Wagner-Whitin (WW) algorithm as a benchmark, the simple incremental rule (IPPA) was compared to three heuristic procedures (LFL, EOQ, and POQ) frequently used in material requirements planning (MRP) lot-sizing research. The incremental rule consistently generated lower total order/setup and carrying costs than the three heuristics across the 3,200 multilevel test situations examined. In many of the test situations, the incremental rule also outperformed the WW benchmark.     

ON THE RELATIVE PERFORMANCE OF FUNCTIONAL AND CELLULAR LAYOUTS- AN ANALYSIS OF THE MODEL-BASED COMPARATIVE STUDIES LITERATURE

Paralleling the increased interest in cellular manufacturing in recent years, a large number of studies have emerged that focus on the relative performance of cell systems and the functionally organized systems they replace. This paper is an analysis of studies that use model-based, controlled experimentation to seek answers to the questions of if, when, and why cellular layouts outperform their functional counterparts. Twenty-four model-based studies are analyzed with respect to their definitions of cellular versus functional layouts, the experimental factors that have been investigated, the results concerning relative performance, and the findings' relevance to layout choice. We conclude that although the comparative studies have been very valuable in their efforts at identifying the factors that embody the essence of cells and shape performance improvements, most of the basic findings are known from past research. Furthermore, the studies' findings cannot assist practitioners in making specific choices between existing layouts and alternative cell systems. However, the totality of the findings reinforce our knowledge of how work systems in general can be designed and organized to reduce throughput time, and can also be used to identify environments and conditions for which conversions to cells may have more or less potential.     

THE ECONOMICS OF CAPACITY AND MARKETING MEASURES IN A SIMPLE MANUFACTURING ENVIRONMENT

As manufacturing firms push to achieve shorter lead times and higher levels of customer service, the basic capability of underlying manufacturing processes must be reexamined. The capacity and operational variability of a process dictate a certain set of realistic performance goals. In this paper, we examine this fundamental relationship from an economic perspective using two levels of analysis. At the aggregate level, we model the manufacturing process as a single server queue and compare the traditional roles of marketing and manufacturing in setting performance and process design parameters. Insights gained at this level are incorporated into the analysis of a realistic multiserver, multistation manufacturing line. We develop an interaction decision tool to guide the selection of process and performance parameters in this more complex environment.     

THE IMPACT OF PROBABILISTIC INFORMATION ON DECISION BEHAVIOR AND PERFORMANCE IN AN EXPERIMENTAL GAME

This research presents the results of a longitudinal experiment using experimental gaming. The results suggest that probabilistic information did change decision behavior and improve subject performance in the experiment. Moreover, there appeared to be a learning effect associated with the use of probabilistic information. Finally, the source of information (externally supplied by the researcher or generated by the subjects themselves) had an impact on decision behavior and performance in the experiment.     

IMPROVING THE DELIVERY OF SPECIAL EDUCATION AND RELATED SERVICES IN PUBLIC SCHOOLS

The utility of organizational behavior management (OBM) for improving the delivery of special education and related services in public school districts was investigated in three experimental studies. Each study employed a multiple baseline design to judge the efficacy of an OBM intervention on service delivery problems common to most public school organizations. The problems and OBM interventions were: (1) expanding the range of functioning of school psychologists through performance feedback; (2) training special service teams to develop valuable individual education programs (IEPs) with a behavioral, in-service training program; and (3) ensuring the implementation of a special education resource room program by means of program consultation. All interventions were implemented by public school program managers and staff. In each study, the particular intervention resulted in improvement in service delivery performance. Results of the studies are discussed within the context of the recently enacted legislation for the education of handicapped children and in terms of generality to mental health, business, and industrial settings.     

EXTERNALITIES IN PROGRAM EVALUATION: THE IMPACT OF A WOMEN'S EMPOWERMENT PROGRAM ON IMMUNIZATION

Impact evaluations of development programs usually do not explicitly take into account externalities on non‐participants. Based on a unique dataset we estimate the direct as well as the spillover effects of Mahila Samakhya, a women's empowerment program in India, on child immunization. The survey covers both participants and non‐participants in program villages, as well as respondents in control villages. We account for participation selection bias using instrumental variables. We propose a direct test for the exclusion restriction using the control villages. We find both direct effects on the immunization rates of participants’ children and significant spillovers on immunization rates of non‐participants’ children. The impact of interventions might be substantially underestimated if such external effects were not taken into account. Alternative estimation methods such as propensity score matching and a regression discontinuity approach yield comparable results.     

IMPACT OF PARTICIPATION IN THE BUDGETARY PROCESS ON MANAGERIAL ATTITUDES AND PERFORMANCE: UNIVERSALISTIC AND CONTINGENCY PERSPECTIVES*

Data from responsibility-center managers reveal that greater budgetary participation contributes to managerial performance and attitudes in high-environmental-uncertainty situations but hampers performance and attitudes in low-uncertainty situations. Higher budgetary participation reduces managers' propensity to create slack in high- (but not in low-) uncertainty conditions.     

COMPARATIVE PRODUCT TESTS IN THE CONSUMER DECISION PROCESS: CORRELATES OF USE AND IMPACT ON SATISFACTION *

Information inputs are an important determinant of the quality of outcomes in the consumer decision process. This paper reports on an exploratory study that examines the perceived use of Consumer Reports product tests in a specific durable-product purchase in a nationwide sample of Consumer Reports subscribers. Perceived use of Consumer Reports is found to be related to performance-oriented shopping, but other situation-related variables are less likely to be associated with use than the shopper's general confidence in the test reports as an information source. Perceived use of the test reports in this study is associated with higher satisfaction with the products purchased.     

A COMPARISON OF ORDER-RELEASE AND DISPATCH RULES FOR THE DYNAMIC WEIGHTED EARLY/TARDY PROBLEM

The early/tardy problem is one of the most vexing pieces of the complex production scheduling decision process. So far most of the research has been on single-machine environments. Hence, we considered the weighted early/tardy scheduling problem in a simulated dynamic multimachine job shop. We analyzed controlled job-release and dispatch rules using time and cost information at a variety of stationary and nonstationary utilization rates, due-date allowances, and early/tardy cost levels. We found a newly developed method for controlling the release for all job operations using early/tardy cost information, superior to other release mechanisms overall in both our stationary and nonstationary analyses. We found immediate release useful at many high utilization conditions and a gateway-only release method best in many low utilization conditions. A modified version of a single-machine early/tardy dispatch method was clearly superior to the dispatch rules for almost all the simulated shop conditions.     

A COMPARISON OF PRODUCTION SCHEDULING POLICIES ON COSTS,SERVICE LEVEL,AND SCHEDULE CHANGES

We consider a single product, single level, stochastic master production scheduling (Mps ) model where decisions are made under rolling planning horizons. Outcomes of interest are cost, service level, and schedule stability. The subject of this research is the Mps control system: the method used in determining the amount of stock planned for production in each time period. Typically, Mps control systems utilize a single buffer stock. Here, two Mps dual-buffer stock systems are developed and tested by simulation. We extend the data envelopment analysis (dea ) methodology to aid in the evaluation of the simulation results, where Dea serves to increase the scope of the experimental design. Results indicate that the dual-buffer control systems outperform existing policies.     

SOME STATISTICAL ISSUES IN THE ESTIMATION OF A SIMPLE COST-VOLUME-PROFIT MODEL*

This paper presents point and interval estimators of both long-run and single-period target quantities in a simple cost-volume-profit (C-V-P) model. This model is a stochastic version of the “accountant's break-even chart” where the major component is a semivariable cost function. Although these features suggest obvious possibilities for practical application, a major purpose of this paper is to examine the statistical properties of target quantity estimators in C-V-P analysis. It is shown that point estimators of target quantity are biased and possess no moments of positive order, but are consistent. These properties are also shared by previous break-even models, even when all parameters are assumed known with certainty. After a test for positive variable margins, Fieller's [6] method is used to obtain interval estimators of relevant target quantities. This procedure therefore minimizes possible ambiguities in stochastic break-even analysis (noted by Ekern [3]).     

COLLABORATION AND EVALUATION IN THE SUPPLY CHAIN: THE IMPACT ON PLANT‐LEVEL ENVIRONMENTAL INVESTMENT

Manufacturing organizations can potentially improve environmental management both by increasing the level of investment in environmental technologies and by shifting that investment away from pollution control and toward pollution prevention. However, managers must not only consider their own manufacturing operations in isolation, but also those of others along the supply chain. This paper explores two dimensions of supply chain activities—collaboration and evaluation—that might be leveraged by plant managers to improve environmental management in their own plant. The linkages with suppliers and customers were assessed. Both customer‐ and plant‐initiated collaboration were found to have a significant effect on the level and form of investment in environmental technologies for a sample of Canadian plants. Of greatest importance, as customer‐initiated collaborative activities increased, plant‐level investment in environmental management was increasingly allocated toward pollution prevention. In contrast, only very limited evidence was found that evaluative activities influenced environmental investment.     

QUANTIFYING THE IMPACT OF INVENTORY HOLDING COST AND REACTIVE CAPACITY ON AN APPAREL MANUFACTURER'S PROFITABILITY

This paper was motivated by the operational problems faced by Northco, a school uniform manufacturer in the Northeastern United States. Northco was facing high working capital costs while also incurring high stockout and markdown costs. This paper models the impact of inventory holding cost and reactive capacity on Northco's targeted understocking and overstocking cost and offers a solution methodology for such problems. We quantify the impact of varying inventory carrying costs (and hence, high working capital costs) on stockout costs and the value of additional capacity. Our results illustrate that apparel manufacturers with high working capital costs, and hence high inventory carrying costs, should target higher stockout costs and achieve lower capacity utilization. The results presented have application beyond Northco because high working capital cost is endemic to many supply chains.     

A COMPARISON OF THE EFFECTS OF EXOGENOUS OIL SUPPLY SHOCKS ON OUTPUT AND INFLATION IN THE G7 COUNTRIES

A comparison of the effects of exogenous shocks to global crude oil production on seven major industrialized economies suggests a fair degree of similarity in the real growth responses. An exogenous oil supply disruption typically causes a temporary reduction in real GDP growth that is concentrated in the second year after the shock. Inflation responses are more varied. The median CPI inflation response peaks after three to four quarters. Exogenous oil supply disruptions need not generate sustained inflation or stagflation. Typical responses include a fall in the real wage, higher short‐term interest rates, and a depreciating currency with respect to the dollar. Despite many qualitative similarities, there is strong statistical evidence that the responses to exogenous oil supply disruptions differ across G7 countries. For suitable subsets of countries, homogeneity cannot be ruled out. A counterfactual historical exercise suggests that the evolution of CPI inflation in the G7 countries would have been similar overall to the actual path even in the absence of exogenous shocks to oil production, consistent with a monetary explanation of the inflation of the 1970s. There is no evidence that the 1973–1974 and 2002–2003 oil supply shocks had a substantial impact on real growth in any G7 country, whereas the 1978–1979, 1980, and 1990–1991 shocks contributed to lower growth in at least some G7 countries. (JEL: E31, E32, Q43)     

MORE MISSING WOMEN,FEWER DYING GIRLS: THE IMPACT OF SEX‐SELECTIVE ABORTION ON SEX AT BIRTH AND RELATIVE FEMALE MORTALITY IN TAIWAN

This study finds that the introduction of sex‐selective abortion in Taiwan due to the legalization of abortion when prenatal sex‐detection technology was already available increased the fraction of males born at higher parities and changed the composition of mothers choosing to give birth. Controlling for compositional changes, we find that access to sex‐selective abortion reduced relative neonatal female mortality rates for higher‐parity births.