Simulation-based performance assessment of master planning approaches in semiconductor manufacturing

Semiconductor manufacturing is confronted with a large number of products whose mix is changing over time, heterogeneous fabrication processes, re-entrant flows of material, and different sources of environmental and system uncertainty. In this context, the mid-term production planning approach, i.e., master planning, typically does not capture the entire complexity of the shop-floor. It deals with an aggregated representation of the production system. There is a need for evaluating the planning algorithm in use while taking the execution level into account. Therefore, we introduce in this paper a simulation-based framework that allows for modeling the behavior of the market demand and the production system. An appropriate performance assessment methodology is proposed. The performance of two heuristic approaches for master planning in semiconductor manufacturing, a genetic algorithm and a rule-based assignment procedure, is evaluated within a rolling horizon setting while considering demand and execution uncertainty. A reduced discrete-event simulation model is used to mimic a one-stage network of wafer fabrication facilities. The results of simulation experiments are discussed.     

REENGINEERING CHANNEL REORDERING PROCESSES TO IMPROVE TOTAL SUPPLY-CHAIN PERFORMANCE

This paper discusses the relationship between business process reengineering and channel performance for firms implementing electronic data interchange (EDI) linkages within the U.S. grocery industry. Both quantitative and qualitative data sources are combined to test the hypothesis that channel transformation involving adoption of EDI and redesign of replenishment processes enables performance improvements more than an order of magnitude greater than implementation of EDI alone. This new process, enabled by EDI, provides retailers with 50- 100% higher inventory turns for products on continuous replenishment processes (CRP) relative to retailer performance using traditional ordering processes. Firms adopting EDI without using CRP to reengineer the ordering processes have failed to realize any statistically significant improvements in either inventory levels or warehouse stockouts. This research provides evidence to support the claims of process reengineering that are common in the popular business press, but for which statistically significant empirical evidence is minimal. The findings of the research also demonstrate the potential improvements that firms can realize through extending the business process reengineering concept to include the firms' entire supply chain.     

部分中间产出作为最终产品的两阶段合作效率

网络DEA模型研究多个进程和多个子系统的复杂系统的效率度量.针对中间产出无法为第2阶段完全消耗的情形,传统DEA模型对系统效率的评价偏高,已有网络DEA模型则对系统效率的评价偏低.本文提出部分中间产出作为最终产品,进入流通渠道的两阶段效率模型,用来测度两阶段生产过程的真实效率.采用乘积形式描述两阶段合作的特征,给出不同...     

Order Management in the Customization‐Responsiveness Squeeze*

Make‐to‐order (MTO) products may be either customized or standard, and customization can occur either at the configuration or component level. Consequently, MTO production processes can be divided into three customization gestalts: non‐customizers, custom assemblers, and custom producers. In this article, we examine how the multilevel nature of customization affects order management in processes that produce complex MTO products. We first empirically validate the existence of the three customization gestalts and subsequently, analyze the order management challenges and solutions in each gestalt in a sample of 163 MTO production processes embedded in seven different supply chains. In the analyses, we follow a mixed‐methods approach, combining a quantitative survey with qualitative interview data. The results show that important contingencies make different order management practices effective in different gestalts. Further qualitative inquiry reveals that some seemingly old‐fashioned practices, such as available‐to‐promise verifications, are effective but commonly neglected in many organizations. The results also challenge some of the conventional wisdom about custom assembly (and indirectly, mass customization). For example, the systematic configuration management methods—conventionally associated with project business environments—appear to be equally important in custom assembly.     

RFID‐Enabled Visibility and Retail Inventory Record Inaccuracy: Experiments in the Field

Accurate inventory records are key to effective store execution, affecting forecasting, ordering, and replenishment. Prior empirical research, however, shows that retailer inventory records are inherently inaccurate. Radio Frequency Identification (RFID) enables visibility into the movement of inventories in the supply chain. Using two different field experiments, the current research investigates the effectiveness of this visibility in reducing retail store inventory record inaccuracy (IRI). Study 1 used an interrupted time‐series design and involved daily physical counts of all products in one category in 13 stores (8 treatments and 5 controls) of a major global retailer over 23 weeks. Results indicate a significant decrease in IRI of approximately 26% due to RFID‐enabled visibility. Using an untreated control group design with pre‐test and post‐test, Study 2 expands the number of categories to five and the number of stores to 62 (31 treatment and 31 control stores). Results show that the effectiveness of RFID in reducing IRI varies by category (ranging from no statistically significant improvement to 81%). Results also suggest that RFID ameliorates the effects of known determinants of IRI and provide the key insight that the technology is most effective for product categories characterized by these determinants.     

Analysis of Two‐Level Support Systems with Time‐Dependent Overflow—A Banking Application

In this paper, we analyze the performance of call centers of financial service providers with two levels of support and a time‐dependent overflow mechanism. Waiting calls from the front‐office queue flow over to the back office if a waiting‐time limit is reached and at least one back‐office agent is available. The analysis of such a system with time‐dependent overflow is reduced to the analysis of a continuous‐time Markov chain with state‐dependent overflow probabilities. To approximate the system with time‐dependent overflow, some waiting‐based performance measures are modified. Numerical results demonstrate the reliability of this Markovian performance approximation for different parameter settings. A sensitivity analysis shows the impact of the waiting‐time limit and the dependence of the performance measures on the arrival rate.     

An Examination of How Supervisors Influence Their Subordinates to Engage in Environmental Behaviors

Employee engagement in environmental behaviors is an important topic in operations management. Drawing upon stakeholder, commitment, and organizational support theories, this study creates and tests an empirical model of how store managers (i.e., supervisors) influence their direct reports (i.e., subordinates) to become engaged in environmental behaviors. Based on a dataset derived from supervisors and their subordinates who are employed at the same grocery store location across a large retail grocery chain, we test our study's nomological model and find support for the linkages proposed. Key research and managerial implications are discussed.     

Bursts and heavy tails of execution time in business processes

This paper investigates the phenomena and effects of heavy tails of execution time in business processes. We approached the heavy tails as a particular variation of business process execution, and analysed them from empirical data of its execution time. The features and possible causes of the heavy tails were investigated. A workflow simulation was conducted to simulate the heavy tails, in order to evaluate quantitatively their effects to business process performance. The simulation outcomes demonstrate that (1) even a heavy-tailed activity in a business process can cause large variation of end-to-end execution times of the process and (2) there are significant prediction gaps resulted by different assumptions of execution times between an exponential distribution and a heavy-tailed distribution.     

The Impact of the Online Channel on Retailers' Performances: An Empirical Evaluation

The use of the Internet as an additional sales channel offers traditional retailers opportunities to reach expanded markets while improving the efficiency of their operations. Although the potential benefits of the online channel are clear, there are significant variations in the scope and depth of online channel use among retailers. Drawing from data on more than 100 publicly traded companies, this study examines the impact of online‐channel use on retailers’ performance. The results suggest that the online channel provides significant improvements in sales, cost, inventory, and return on investments. In addition, we find that the timing of online‐channel adoption does not play a significant role in performance improvement, but having a local store presence does.     

Analyzing the dependences of multi-category purchases on interactions of marketing variables

We extend the usual specification of the multivariate probit model frequently used to analyze multi-category purchase incidence data by introducing interaction effects between marketing variables. Models are estimated by a Markov Chain Monte Carlo simulation method using 24,047 shopping visits made by a random sample of 1500 households in one specific grocery store over a one year period. Our data refer to a total of 25 food and non-food product categories and include socio-demographic household attributes in addition to purchases and marketing variables. Information criteria agree on the superiority of the extended specification. Estimation results demonstrate that many interaction effects are erroneously attributed to the main effects of marketing variables if one applies the usual specification instead. We derive managerial implications with respect to sales revenue by stochastic simulation. If managers base decisions on the usual specification in spite of its worse statistical performance, they run the risk to overestimate sales revenue increases due to sales promotion activities.     

平台服务和物流服务对网络商家信心的影响——商家信誉的调节作用

在电子商务平台中,商家日常经营所需的服务与传统零售业有所不同,主要包括平台服务和物流服务两种。商家信心决定着平台的生存发展,但尚未有文献从信心视角对平台服务和物流服务展开研究。本文使用3995位淘宝店铺经营者的调查数据,建立次序回归模型分析发现:平台服务和物流服务都对商家信心有正向影响;商家信誉具有调节作用,随着信誉等级的提高,平台服务对商家信心的影响逐渐增强;而信誉等级较低的商家信心更容易受物流服务影响。     

Innovation Strategy,Human Resource Policy,and Firms' Revenue Growth: The Roles of Environmental Uncertainty and Innovation Performance*

This study investigates the interactions of innovation strategy execution and innovation‐focused human resource (HR) policy adoption on innovation performance and revenue growth. In addition, we investigate the moderating role of environmental uncertainty on the effects of innovation strategy execution and innovation‐focused HR policy on innovation performance. Results show that the interaction of innovation strategy execution and innovation‐focused HR policy is positively related to innovation performance. Results also show that environmental uncertainty positively moderates the innovation strategy execution–innovation performance relationship. Finally, innovation performance mediates the interaction of innovation strategy execution and environmental uncertainty on firms’ revenue growth. Implications of these findings for theory and practice are discussed.     

Analysis of Effects of Operational Execution on Repeat Purchasing for Heterogeneous Customer Segments

Many retailers are increasingly turning to home delivery as a new arena of operational competition. This study controlled for industry by investigating the online home delivery grocery business, and an analysis of 1,919 customers of home delivery grocers identified four groups of online customers based on reasons for selecting this service. These four groups were next linked to operational execution in terms of service, product, and Internet quality, and found to vary in predicable ways. Subsequent to the initial data collection, five month's of post hoc longitudinal purchasing history was collected on the four groups of online customers to determine the relative profitability. Finally, as a follow‐on analysis, the study used regression to predict future consumer purchases based upon operational execution. Time savings and service quality emerged as the two most important independent variables in terms of future buying from such online home delivery services.     

Sequence Matters: Shelf‐Space Allocation under Dynamic Customer‐Driven Substitution

Customers who face a stockout situation often decide to purchase a different product in the same category. We analyze the resulting dynamic substitution problem in a retail environment, where customers serve themselves from the store shelves, such that the sequence of customer arrivals affects how scarce products are allocated to customers. We consider a setting with constrained shelf space, and we study how a retailer should optimally allocate such space between substitute products. We characterize environments where the sequence of customer arrivals can have a substantial impact on profitability.     

The Role of Slotting Fees in the Coordination of Assortment Decisions

Large numbers of new products introduced annually by manufacturers may strain the relationship between retailers and manufacturers regarding assortments carried by retailers. For example, many retailers in the grocery industry will agree to broaden their assortments only if the manufacturer agrees to pay slotting fees for the new products. We investigate the role played by slotting fees in coordinating the assortment decisions in a supply chain. To do so, we study a single‐retailer, single‐manufacturer supply chain, where the retailer decides what assortment to offer to end customers. Double marginalization results in a discrepancy between the retailer's optimal assortment and the assortment that maximizes total supply chain profits. We consider a payment scheme that is analogous to slotting fees used in the grocery industry: the manufacturer pays the retailer a per‐product fee for every product offered by the retailer in excess of a certain target level. We show that, if the wholesale price is below some threshold level, this payment scheme induces the retailer to offer the supply‐chain‐optimal assortment and makes both parties better off.     

Maximizing Revenue Through Two‐Dimensional Shelf‐Space Allocation

We consider the problem of optimally allocating contiguous rectangular presentation spaces in order to maximize revenues. Such problems are encountered in the arrangement of products in retail shelf‐space and in the design of feature advertising displays or webpages. Specifically, we allow (i) the shape of a product's presentation to have a vertical as well as a horizontal component and (ii) displays to extend across multiple shelves for in‐store presentations. Since the vertical location of the shelf on which a product is displayed affects its sales, each vertical location is assigned its own effectiveness with regard to revenue generation. The problem of maximizing the total weighted revenue of a display is strongly NP‐hard. Therefore, we decompose it into two subproblems. The first consists of allocating products to different cabinets. In the second, within each cabinet, each product's units are arranged in a contiguous rectangle and assigned a location. These subproblems are solved using an innovative approach that uses a combination of integer programming and an algorithm for the maximum‐weight independent set problem. Based on computational studies on both real‐world and simulated data, we demonstrate the efficiency and effectiveness of our approach. Specifically, the revenue generated by this scheme is within 1% of the optimum for actual data and within 5% for simulated data.     

Self‐Service Operations at Retail Stores: The Role of Inter‐Customer Interactions

Inter‐customer interactions are important to the operation of self‐services in retail settings. More specifically, when self‐service terminals are used as part of customers’ checkout processes in retail operations without the explicit involvement of retailers as the direct service providers, inter‐customer interactions become a significant managerial issue. In this article, we examine the impact of inter‐customer interactions at retail self‐service terminals on customers’ service quality perceptions and repeat purchase intentions at retail stores. We conduct a scenario‐based experimental design (N = 674) using a 2 × 2 factorial design in which inter‐customer interactions are divided into “positive” vs. “negative” and occur during the “waiting” or during the actual “transaction” stages of self‐services at a retail store. We use attribution theory to develop the hypotheses. The results demonstrate that, through their interactions, fellow customers can exert influences on a focal customer's quality perceptions and repeat purchasing intentions toward a retail store. Furthermore, these influences were impacted by how customers attribute blame or assign responsibility toward the retail store. Service operations managers should leverage these interactions by designing into self‐service settings the capacities and interfaces that are best suited for customers’ co‐production of their self‐service experiences.     

A characterisation of logistics networks for product recovery

Recovery of used products is receiving much attention recently due to growing environmental concern. Efficient implementation requires appropriate logistics structures to be set up for the arising goods flow from users to producers. We investigate the design of such logistics networks. As a basis for our analysis we review recent case studies on logistics network design for product recovery in different industries. We identify general characteristics of product recovery networks and compare them with traditional logistics structures. Moreover, we derive a classification scheme for different types of recovery networks.     

Managing Retail Budget Allocation between Store Labor and Marketing Activities

The performance of a retail store depends on its ability to attract customer traffic, match labor with incoming traffic, and convert the incoming traffic into sales. Retailers make significant investments in marketing activities (such as advertising) to bring customers into their stores and in‐store labor to convert that traffic into sales. Thus, a common trade‐off that retail store managers face concerns the allocation of a store's limited budget between advertising and labor to enhance store‐level sales. To explore that trade‐off, we develop a centralized model to allocate limited store budget between store labor and advertising with the objective of maximizing store sales. We find that a store's inherent potential to drive traffic plays an important role, among other factors, in the relative allocation between advertising and store labor. We also find that as advertising instruments become more effective in bringing traffic to stores, managers should not always capitalize this effectiveness by increasing their existing allocations to advertising. In addition, we discuss a decentralized setting where budget allocation decisions cannot be enforced by a store manager and present a simple mechanism that can achieve the centralized solution. In an extension, we address the budget allocation problem in the presence of marketing efforts to shift store traffic from peak to off peak hours and show that our initial findings are robust. Further, we illustrate how the solution from the budget allocation model can be used to facilitate store level sales force planning/scheduling decisions. Based on the results of our model, we present several insights that can help managers in budget allocation and sales force planning.     

Integrating the Data Envelopment Analysis and the Balanced Scorecard approaches for enhanced performance assessment

This article presents the development of a conceptual framework which aims to assess Decision Making Units (DMUs) from multiple perspectives. The proposed conceptual framework combines the Balanced Scorecard (BSC) method with the non-parametric technique known as Data Envelopment Analysis (DEA) by using various interconnected models which try to encapsulate four perspectives of performance (financial, customers, internal processes, learning and growth).The practical relevance of the conceptual model has been tested by using it to assess the performance of DMUs in a multinational company which operates in two business areas. Various models were developed with the collaboration of the directors of the company in order to conceive an appropriate and consensual framework, which may provide useful information for the company. The application of the conceptual framework provides structured information regarding the performance of each DMU (from multiple perspectives) and ways to improve it. By integrating the BSC and the DEA approaches this research helps to identify where there is room for improving organisational performance and points out opportunities for reciprocal learning between DMUs. In doing so, this article provides a set of recommendations relating to the successful application of DEA and its integration with the BSC, in order to promote a continuous learning process and to bring about improvements in performance.