Showing papers in "Production and Operations Management in 2009"
TL;DR: In this paper, the authors provide a conceptual framework that reflects the joint activities of risk assessment and risk mitigation that are fundamental to disruption risk management in supply chains, and consider empirical results from a rich data set covering the period 1995-2000 on accidents in the U. S. Chemical Industry.
Abstract: There are two broad categories of risk affecting supply chain design and management: (1) risks arising from the problems of coordinating supply and demand, and (2) risks arising from disruptions to normal activities. This paper is concerned with the second category of risks, which may arise from natural disasters, from strikes and economic disruptions, and from acts of purposeful agents, including terrorists. The paper provides a conceptual framework that reflects the joint activities of risk assessment and risk mitigation that are fundamental to disruption risk management in supply chains. We then consider empirical results from a rich data set covering the period 1995–2000 on accidents in the U. S. Chemical Industry. Based on these results and other literature, we discuss the implications for the design of management systems intended to cope with supply chain disruption risks.
1,771 citations
TL;DR: In this article, the authors review the sustainability themes covered in the first 50 issues of Production and Operations Management and conclude with some thoughts on future research challenges in sustainable operations management, including integrating environmental, health, and safety concerns with green-product design, lean and green operations, and closed-loop supply chains.
Abstract: Operations management researchers and practitioners face new challenges in integrating issues of sustainability with their traditional areas of interest. During the past 20 years, there has been growing pressure on businesses to pay more attention to the environmental and resource consequences of the products and services they offer and the processes they deploy. One symptom of this pressure is the movement towards triple bottom line reporting (3BL) concerning the relationship of profit, people, and the planet. The resulting challenges include integrating environmental, health, and safety concerns with green-product design, lean and green operations, and closed-loop supply chains. We review these and other “sustainability” themes covered in the first 50 issues of Production and Operations Management and conclude with some thoughts on future research challenges in sustainable operations management.
1,350 citations
TL;DR: In this article, the authors investigated the long-term stock price effects and equity risk effects of supply chain disruptions based on a sample of 827 disruption announcements made during 1989-2000.
Abstract: This paper investigates the long-term stock price effects and equity risk effects of supply chain disruptions based on a sample of 827 disruption announcements made during 1989–2000. Stock price effects are examined starting one year before through two years after the disruption announcement date. Over this time period the average abnormal stock returns of firms that experienced disruptions is nearly –40%. Much of this underperformance is observed in the year before the announcement, the day of the announcement, and the year after the announcement. Furthermore, the evidence indicates that firms do not quickly recover from the negative effects of disruptions. The equity risk of the firm also increases significantly around the announcement date. The equity risk in the year after the announcement is 13.50% higher when compared to the equity risk in the year before the announcement.
1,124 citations
TL;DR: This paper provides a comprehensive survey of research on appointment scheduling in outpatient services and identifies future research directions that provide opportunities to expand existing knowledge and close the gap between theory and practice.
Abstract: This paper provides a comprehensive survey of research on appointment scheduling in outpatient services. Effective scheduling systems have the goal of matching demand with capacity so that resources are better utilized and patient waiting times are minimized. Our goal is to present general problem formulation and modeling considerations, and to provide taxonomy of methodologies used in previous literature. Current literature fails to develop generally applicable guidelines to design appointment systems, as most studies have suggested highly situation-specific solutions. We identify future research directions that provide opportunities to expand existing knowledge and close the gap between theory and practice.
928 citations
TL;DR: In this article, the role of supply management capabilities in green supply is investigated and it is shown that capabilities appropriate for green supply are developed by a proactive corporate environmental stance and by a more strategic purchasing and supply management approach.
Abstract: Managers realize that they should avoid complex green supply initiatives when they do not have the capabilities to implement them. However, they have little guidance on how these capabilities can be developed. This paper provides an initial analysis of the role of supply management capabilities in green supply. We argue that the implementation of green supply is better explained by focusing on the development and deployment of an organization's specialized internal resources, rather than by the more usual focus on external environmental pressures on a firm. Further, we argue that capabilities appropriate for green supply are developed by a proactive corporate environmental stance and by a more strategic purchasing and supply management approach.
We test our model using data from a two-phase survey of 70 operating units within UK public limited companies. Our results indicate support for our conjecture that supply management capabilities are jointly developed by a proactive corporate environmental approach and a strategic purchasing and supply process. Our study results should be useful to business strategists, regulators, and researchers interested in the predictors of corporate green behavior. They should also assist future researchers in many branches of environmental management who are seeking to explore the role of the internal capabilities of firms in supporting environmental management.
905 citations
TL;DR: This paper conducted an empirical analysis of the environmental performance of 17,499 U.S. manufacturing establishments during the time period 1991-1996 and found that those establishments that adopt the quality management standard ISO 9000 are more likely to adopt the environmental management standardISO 14000.
Abstract: Lean production may have a significant public good spillover—improved environmental performance. However, empirical evidence of the link between lean production practices and environmental performance has not resolved the nature of the relationship. To explore this issue, we conduct an empirical analysis of the environmental performance of 17,499 U.S. manufacturing establishments during the time period 1991–1996. We find that those establishments that adopt the quality management standard ISO 9000 are more likely to adopt the environmental management standard ISO 14000. We also find strong evidence that lean production, as measured by ISO 9000 adoption and low chemical inventories, is complementary to waste reduction and pollution reduction.
896 citations
TL;DR: In this paper, the authors develop a model that captures key attributes of such a setting, including various sources of inefficiency, and identify a number of counterintuitive structural properties, and examine ways to adjust the manufacturer-reseller relationship that have been observed in industry.
Abstract: A number of factors, including developments in Internet-based commerce and third-party logistics, have led many companies to consider engaging in direct sales. Such a company may at once be both a supplier to and a direct competitor of any existing reseller partners (e.g., land-based retailers), which can result in “channel conflict.” This can have momentous implications for distribution strategy.
To generate managerial insights into this important issue, we develop a model that captures key attributes of such a setting, including various sources of inefficiency. We examine these in detail and identify a number of counterintuitive structural properties. For instance, the addition of a direct channel alongside a reseller channel is not necessarily detrimental to the reseller, given the associated adjustment in the manufacturer's pricing. In fact, both parties can benefit.
Finally, we examine ways to adjust the manufacturer-reseller relationship that have been observed in industry. These include changes in wholesale pricing, paying the reseller a commission for diverting customers toward the direct channel, or conceding the demand fulfillment function entirely to the reseller. The latter two schemes could be mutually beneficial in that they achieve a division of labor according to each channel's competitive advantage.
874 citations
TL;DR: This paper considers logistics network design in a reverse logistics context with a generic facility location model and uses this model to analyze the impact of product return flows on logistics networks.
Abstract: Efficient implementation of closed-loop supply chains requires setting up appropriate logistics structures for the arising flows of used and recovered products. In this paper we consider logistics network design in a reverse logistics context. We present a generic facility location model and discuss differences with traditional logistics settings. Moreover, we use our model to analyze the impact of product return flows on logistics networks. We show that the influence of product recovery is very much context dependent. While product recovery may efficiently be integrated in existing logistics structures in many cases, other examples require a more comprehensive approach redesigning a company's logistics network in an integral way
800 citations
TL;DR: A survey of the recent literature on call center operations management can be found in this article, where the authors identify a handful of broad themes for future investigation while also pointing out several very specific research opportunities.
Abstract: Call centers are an increasingly important part of today's business world, employing millions of agents across the globe and serving as a primary customer-facing channel for firms in many different industries. Call centers have been a fertile area for operations management researchers in several domains, including forecasting, capacity planning, queueing, and personnel scheduling. In addition, as telecommunications and information technology have advanced over the past several years, the operational challenges faced by call center managers have become more complicated. Issues associated with human resources management, sales, and marketing have also become increasingly relevant to call center operations and associated academic research.
In this paper, we provide a survey of the recent literature on call center operations management. Along with traditional research areas, we pay special attention to new management challenges that have been caused by emerging technologies, to behavioral issues associated with both call center agents and customers, and to the interface between call center operations and sales and marketing. We identify a handful of broad themes for future investigation while also pointing out several very specific research opportunities.
776 citations
TL;DR: The unified services theory (UST) as discussed by the authors defines a service production process as one that relies on customer inputs; customers act as suppliers for all service processes and provides a common reference point to which services management researchers can anchor future theory-building and theory-testing research.
Abstract: Diverse businesses, such as garbage collection, retail banking, and management consulting are often tied together under the heading of “services”, based on little more than a perception that they are intangible and do not manufacture anything. Such definitions inadequately identify managerial and operational implications common among, and unique to, services. We present a “Unified Services Theory” (UST) to clearly delineate service processes from non-service processes and to identify key commonalities across seemingly disparate service businesses. The UST defines a service production process as one that relies on customer inputs; customers act as suppliers for all service processes. Non-services (such as make-to-stock manufacturing) rely on customer selection of outputs, payment for outputs, and occasional feedback, but production is not dependent upon inputs from individual customers. The UST reveals principles that are common to the wide range of services and provides a unifying foundation for various theories and models of service operations, such as the traditional “characteristics of services” and Customer Contact Theory. The UST has significant operational corollaries pertaining to capacity and demand management, service quality, services strategy, and so forth. The UST provides a common reference point to which services management researchers can anchor future theory-building and theory-testing research.
726 citations
TL;DR: In this article, the authors develop models to support a manufacturer's recovery strategy in the face of a competitive threat on the remanufactured product market, and find that a firm may choose to remanufacture or preemptively collect its used products to deter entry even when the firm would not have chosen to do so under a pure monopoly environment.
Abstract: Manufacturers often face a choice of whether to recover the value in their end-of-life products through remanufacturing. In many cases, firms choose not to remanufacture, as they are (rightly) concerned that the remanufactured product will cannibalize sales of the higher-margin new product. However, such a strategy may backfire for manufacturers operating in industries where their end-of-life products (cell phones, tires, computers, automotive parts, etc.) are attractive to third-party remanufacturers, who may seriously cannibalize sales of the original manufacturer. In this paper, we develop models to support a manufacturer's recovery strategy in the face of a competitive threat on the remanufactured product market. We first analyze the competition between new and remanufactured products produced by a monopolist manufacturer and identify conditions under which the firm would choose not to remanufacture its products. We then characterize the potential profit loss due to external remanufacturing competition and analyze two entry-deterrent strategies: remanufacturing and preemptive collection. We find that a firm may choose to remanufacture or preemptively collect its used products to deter entry, even when the firm would not have chosen to do so under a pure monopoly environment. Finally, we discuss conditions under which each strategy is more beneficial.
TL;DR: In this article, the authors developed a framework for analyzing the profitability of reuse activities and showed how the management of product returns influences operational requirements, and how operational issues are strongly affected by the approach used to manage product returns.
Abstract: Firms are often encouraged to offer environmentally friendly products as a demonstration of corporate citizenship. However, this may prove to be an unrealistic expectation since a rational firm will only engage in profitable ventures; those that increase shareholder wealth. We develop a framework for analyzing the profitability of reuse activities and show how the management of product returns influences operational requirements. We show that the acquisition of used products may be used as the control lever for the management and profitability of reuse activities. These activities, termed product acquisition management, affect several important business decisions. First, if a firm is to pursue reuse activities, these reuse activities must be value-creating. Second, if a firm is to compete by offering remanufactured products, then we show how product returns management influences the overall profitability of such activities via a trial and error EVA approach. Third, we show how operational issues are strongly affected by the approach used to manage product returns. There is a need for future research specifying the mathematical relationship between acquisition price and the nominal quality of the returned product.
TL;DR: In this article, the authors used a large, random sample of manufacturing sites to investigate quality management practices and performance and found that employee commitment, shared vision, and customer focus combine to yield a positive correlation with quality outcomes.
Abstract: In his landmark article on total quality management, Powell (1995) lamented the lack of large scale studies investigating quality management practices and performance. This study begins to fill that void using a large, random sample of manufacturing sites. The results show that quality practices can be categorized into nine dimensions. However, not all of them contribute to superior quality outcomes. “Employee commitment,” “shared vision,” and “customer focus” combine to yield a positive correlation with quality outcomes. Conversely, other “hard” quality practices, such as “benchmarking,” “cellular work teams,” “advanced manufacturing technologies,” and “close supplier relations” do not contribute to superior quality outcomes.
TL;DR: In this article, an agenda for service operations management (SOM) research is presented, motivated by the need for an SOM research agenda and a research framework that provides a broad-based picture of key architectural elements in the SOM research landscape.
Abstract: This paper offers insights regarding an agenda for service operations management (SOM) research First, we motivate the need for an SOM research agenda Second, we offer a research framework that paints a broad-based picture of key architectural elements in the SOM research landscape The framework builds upon prior and emerging research for designing, delivering and evaluating services Third, in order to stimulate future research in SOM, we use this framework to hone in on five understudied and emerging research themes that underpin our proposed SOM research agenda
TL;DR: In this paper, the authors address the question: "To what extent do manufacturing plants view competitive priorities as trade-offs?" They employ survey data collected from managers and operators in 110 plants that have recently implemented AMT.
Abstract: A heated debate continues over the need for trade-offs in operations strategy. Some researchers call for plants to focus on a single manufacturing capability and devote their limited resources accordingly, while others claim that advanced manufacturing technology (AMT) enables concurrent improvements in quality, cost, flexibility, and delivery. Yet there is little empirical evidence for or against the trade-off model. In response, this study addresses the question: “To what extent do manufacturing plants view competitive priorities as trade-offs?” We employ survey data collected from managers and operators in 110 plants that have recently implemented AMT. Our findings suggest that trade-offs remain. However, perceived differences in competitive priorities are subtle and may vary across levels of the plant hierarchy. (COMPETITIVE PRIORITIES; OPERATIONS STRATEGY; SURVEY RESEARCH/DESIGN)
TL;DR: In this paper, the authors explored two dimensions of supply chain activities (collaboration and evaluation) that might be leveraged by plant managers to improve environmental management in their own plant.
Abstract: 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.
TL;DR: In this paper, the authors present a two-period model of remanufacturing in the face of competition, where an original equipment manufacturer (OEM) competes with a local remanufacturer (L) under many reverse logistics configurations for the returned items.
Abstract: We present a two-period model of remanufacturing in the face of competition. In our model, an original equipment manufacturer (OEM) competes with a local remanufacturer (L) under many reverse logistics configurations for the returned items. After establishing the Nash Equilibrium in the second period sub-game, we use numerical experiments for comparative statics. OEM wants to increase L'S remanufacturing cost. Surprisingly, while L competes in the sales market, she has incentives to reduce oem's remanufacturing cost. A social planner who wants to increase remanufacturing can give incentives to the OEM to increase the fraction available for remanufacturing, or reduce his remanufacturing costs.
TL;DR: This paper examined the relationship between lean manufacturing practices and environmental performance as measured in terms of air emissions and resource use, and found some evidence to support the link between lean practices and resource efficiency.
Abstract: We examine the relationship between lean manufacturing practices and environmental performance as measured in terms of air emissions and resource use. We draw on two unique surveys of 31 automobile assembly plants in North America and Japan, which contain information on manufacturing practice and environmental performance, as well as in-depth interviews with 156 plant level employees at 17 assembly plants. Our survey results and interviews suggest that lean management and reduction of air emissions of volatile organic compounds (vocs) are associated negatively. Lean manufacturing practices contribute to more efficient use of paints and cleaning solvents, but these in-process changes are not sufficient to meet the most stringent air regulations. We found some evidence to support the link between lean practices and resource efficiency. While our survey results were in hypothesized direction, they were not statistically significant. In-depth semi-structured interviews, however, suggest a more robust relationship, and we use them to describe some mechanisms by which all three aspects of lean management (buffer minimization, work systems, and human resource management) may be related to environmental management practices and performance.
TL;DR: In this paper, the authors report empirical insights to EMS practices based on the largest EMS survey of manufacturing firms in the United States and test for a relationship between environmental management systems and perceived operations performance while considering direct and indirect effects of various environmental practices.
Abstract: 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. (ENVIRONMENTAL MANAGEMENT SYSTEMS; ENVIRONMENTAL PRACTICES; ENVIRONMENTAL PERFORMANCE; MULTIMETHODS; STRUCTURAL EQUATION MODELING)
TL;DR: In this article, the authors use information from the technological history of the disk drive industry to examine the usefulness of the S-curve framework for managers at the firm level in planning for new technology development.
Abstract: The technology S-curve is a useful framework describing the substitution of new for old technologies at the industry level. In this paper I use information from the technological history of the disk drive industry to examine the usefulness of the S-curve framework for managers at the firm level in planning for new technology development. Because improvements in over-all disk drive product performance result from the interaction of improved component technologies and new architectural technologies, each of these must be monitored and managed. This paper focuses on component technology S-curves, and a subsequent paper, also published in this issue of the journal, examines architectural technology Scurves. Improvement in individual components followed S-curve patterns, but I show that the flattening of S-curves is a firm-specific, rather than uniform industry phenomenon. Lack of progress in conventional technologies may be the result, rather than the stimulus, of a forecast that the conventional technology is maturing, and some firms demonstrated the ability to wring far greater levels of performance from existing component technologies than other firms. Attacking entrant firms evidenced a distinct disadvantage versus incumbent firms in developing and using new component technologies. Firms pursuing aggressive Scurve switching strategies in component technology development gained no strategic advantage over firms whose strategies focused on extending the life of established component technologies.
TL;DR: In this paper, the authors conducted an exploratory study into the global spread of ISO 14000 and found that exports, environmental attitudes, and ISO 9000 certification count were significant factors in the diffusion of ISO14000.
Abstract: The ISO 9000 series of quality management systems standards and the more recent ISO 14000 environmental management systems standards have generated much controversy among practitioners. Although ISO 9000 has become a de facto requirement for many firms, its effects are poorly understood, and similarly the value and domain of applicability of ISO 14000 have been questioned. This paper reports on an exploratory study into the global spread of ISO 14000. We interviewed practitioners worldwide to identify factors that they believe explain differences between national ISO 14000 certification counts. We then collected quantititive data for these factors and, using regression analysis, we found that exports, environmental attitudes (combined with economic development), and ISO 9000 certification count were significant. The fact that ISO 9000 appears as an important factor explaining diffusion of ISO 14000 certifications suggests that the drivers behind the two have significant overlap. This indicates that, although ISO 14000 is an environmental standard, many of the factors driving national certification patterns are not at all environmental in nature, and that ISO 14000 therefore needs to be studied from a broader perspective than from a purely environmental point of view.
TL;DR: In this paper, the authors test the hypothesis that firms obtain ISO 9000 certification to comply with government and customer demands by estimating a probit model of the certification decision and find that other factors related to quality management and quality-based competition explain the adoption decision.
Abstract: Proponents of iso 9000 certification claim that it is a low-cost signal of a firm's commitment to quality and a meaningful component of total quality management (TQM). Critics claim that it has little relation to TQM and is a tariff on international trade. We test the hypothesis that firms obtain ISO 9000 certification to comply with government and customer demands by estimating a probit model of the certification decision. The results support the view of proponents of ISO 9000. After controlling for regulatory and customer pressures to obtain ISO 9000, other factors related to quality management and quality-based competition explain the adoption decision.
TL;DR: In this article, the authors investigate two very distinct types of arrangements between an assembler/retailer and its suppliers, and derive the revenue shares the assembler should select in order to maximize its own profits.
Abstract: Assembly and kitting operations, as well as jointly sold products, are rather basic yet intriguing A decentralized supply chains, where achieving coordination through appropriate incentives is very important, especially when demand is uncertain. We investigate two very distinct types of arrangements between an assembler/retailer and its suppliers. One scheme is a vendor-managed inventory with revenue sharing, and the other a wholesale-price driven contract. In the VMI case, each supplier faces strategic uncertainty as to the amounts of components, which need to be mated with its own, that other suppliers will deliver. We explore the resulting components' delivery quantities equilibrium in this decentralized supply chain and its implications for participants' and system's expected profits. We derive the revenue shares the assembler should select in order to maximize its own profits. We then explore a revenue-plus-surplus-subsidy incentive scheme, where, in addition to a share of revenue, the assembler also provides a subsidy to component suppliers for their unsold components. We show that, by using this two-parameter contract, the assembler can achieve channel coordination and increase the profits of all parties involved. We then explore a wholesale-price-driven scheme, both as a single lever and in combination with buybacks. The channel performance of a wholesale-price-only scheme is shown to degrade with the number of suppliers, which is not the case with a revenue-share-only contract.
TL;DR: In this article, a stakeholder perspective is integrated into the resource-based view of the firm, to analyze the mechanisms that link the adoption of the international Environmental Management Standard ISO 14001 to firms' competitive advantage.
Abstract: This paper integrates a stakeholder perspective into the resource-based view of the firm, to analyze the mechanisms that link the adoption of the international Environmental Management Standard ISO 14001 to firms' competitive advantage. This paper shows that the perceived competitiveness impact of the standard depends mostly on the involvement of firms' external stakeholders (distributors, customers, community members, and regulatory agencies) in its design. ISO 14001 is a process standard, and it is difficult for stakeholders to get credible information on the effectiveness of the standard if they are not involved in its design. Stakeholders' involvement in a firm's ISO 14001 standard becomes a valuable organizational capability, which is difficult to imitate by competitors. The analysis is supported by primary data collected from a questionnaire mailed to 152 firms, resulting in 55 observations representing 30% of the total number of firms certified in the U.S. in August 1998.
TL;DR: In this article, the authors examined supply chain design strategies for a specific type of perishable product (fresh produce) using melons and sweet corn as examples, and showed 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.
Abstract: 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.
TL;DR: In this article, the authors review current models of customer behavior in the revenue management and auction literatures and suggest several future research directions for customer behavior modeling in the operations management community.
Abstract: Customer behavior modeling has been gaining increasing attention in the operations management community. In this paper we review current models of customer behavior in the revenue management and auction literatures and suggest several future research directions.
TL;DR: Approximations for a basic queueing model, which has m identical servers in parallel, unlimited waiting room, and the first-come first-served queue discipline, are developed and evaluated and are useful supplements to algorithms for computing the exact values that have been developed in recent years.
Abstract: Queueing models can usefully represent production systems experiencing congestion due to irregular flows, but exact analyses of these queueing models can be difficult. Thus it is natural to seek relatively simple approximations that are suitably accurate for engineering purposes. Here approximations for a basic queueing model are developed and evaluated. The model is the GI/G/m queue, which has m identical servers in parallel, unlimited waiting room, and the first-come first-served queue discipline, with service and interarrival times coming from independent sequences of independent and identically distributed random variables with general distributions. The approximations depend on the general interarrival-time and service-time distributions only through their first two moments. The main focus is on the expected waiting time and the probability of having to wait before beginning service, but approximations are also developed for other congestion measures, including the entire distributions of waiting time, queue-length and number in system. These relatively simple approximations are useful supplements to algorithms for computing the exact values that have been developed in recent years. The simple approximations can serve as starting points for developing approximations for more complicated systems for which exact solutions are not yet available. These approximations are especially useful for incorporating GI/G/m models in larger models, such as queueing networks, wherein the approximations can be components of rapid modeling tools.
TL;DR: It is found that lead-time variability exacerbates variance amplification in a supply chain, and that information sharing and information quality are highly significant.
Abstract: We use a simulation model called ‘SISCO’ to examine the effects in supply chains of stochastic lead times and of information sharing and quality of that information in a periodic order-up-to level inventory system. We test the accuracy of the simulation by verifying the results in Chen et al. (2000a) and Dejonckheere et al. (2004). We find that lead-time variability exacerbates variance amplification in a supply chain, and that information sharing and information quality are highly significant. For example, using the assumptions in Chen et al. (2000a) and Dejonckheere et al. (2004), we find in a numerical experiment of a customer-retailer-wholesaler-distributor-factory supply chain that variance amplification is attenuated by nearly 50 percent at the factory due to information sharing. Other assumptions we make are based on interviews or conversations with managers at large supply chains.
TL;DR: In this article, the authors present the results of a natural experiment conducted at a U.S. high-tech manufacturer, where the adoption, at a single point in time, of a comprehensive enterprise information system throughout the functional groups charged with customer order fulfillment.
Abstract: This paper presents the results of a natural experiment conducted at a U.S. high-tech manufacturer. The experiment had as its treatment the adoption, at a single point in time, of a comprehensive enterprise information system throughout the functional groups charged with customer order fulfillment. This information technology (it) adoption was not accompanied by substantial contemporaneous business process changes. Immediately after adoption, lead time and on-time delivery performance suffered, causing a “performance dip” similar to those observed after the introduction of capital equipment onto shop floors. Lead times and on-time delivery percentages then improved along a learning curve. After several months, performance in these areas improved significantly relative to preadoption levels. These observed performance patterns could not be well explained by rival causal factors such as order, production, and inventory volumes; head count; and new product introductions. Thus, this longitudinal research presents initial evidence of a causal link between IT adoption and subsequent improvement in operational performance measures, as well as evidence of the timescale over which these benefits appear.
TL;DR: In this paper, the authors reviewed the manuscripts focused on supply chain management that had been published in Production and Operations Management (POM) over roughly 15 years (1992 to 2006).
Abstract: We reviewed the manuscripts focused on Supply Chain Management that had been published in Production and Operations Management (POM) over roughly 15 years (1992 to 2006). The manuscripts covered dealt with topics including supply chain design, uncertainty and the bullwhip effect, contracts and supply chain coordination, capacity and sourcing decisions, applications and practice, and teaching supply chain management. In the process of this review, we highlight the significant contribution of POM to the field of supply chain management, and illustrate how this body of work has served to further the mission of the journal. We then highlight works from this group along with the discussion of selected papers from other top journals in an effort to provide a reasonably complete overview of important issues addressed in recent supply chain management research. Using our research survey and conceptual overview of the area as a foundation, we offer comments which highlight opportunities and suggest ideas on how to usefully expand the body of work in the supply chain management area.