Technologies of the spouse: intimate surveillance in Senegalese transnational marriages

Rapid advances in communication technology in the last 20 years have enabled migrants to sustain social and economic investment in multiple geographic locations, or, to be transnational. In this article, by analysing non‐migrant Senegalese women's experiences in marriages with migrant Senegalese men, I critically engage in discussions about the role of technology in transnational family dynamics. In the intimate negotiations of transnational married life, these women feel profoundly ambivalent about the role of communication technologies in their lives. Instead of enabling ‘emotional closeness’, the virtual presence of their absent husbands frequently represents a spectre of suspicion, control and surveillance.     

EVALUATING THE TRADE-OFFS BETWEEN IDLING AND SHUTTING DOWN PRODUCTION LINES IN PROCESS INDUSTRIES

The costs of starting-up and shutting down production lines (and plants) in a process industry are often quite high. Therefore, when a plant's capacity significantly exceeds its forecast demand over an annual planning horizon, a manufacturer must either plan temporary production line shutdowns during the year, or plan to temporarily idle production lines without formally shutting line(s) down. The trade-offs between these two strategies can be complex. In this paper, we propose a methodology to evaluate the impact of both strategies on a plant's production costs by developing an analytical model based on the authors' experience with several process industries.     

APPOINTMENT POLICIES IN SERVICE OPERATIONS: A CRITICAL ANALYSIS OF THE ECONOMIC FRAMEWORK

In this paper we review the literature on appointment policies, specifically in terms of the objective function commonly used and the assumptions made about the behavior of demand. First, we provide an economic framework to analyze the problem. Based on this framework we make a critical analysis of the objective functions used in the literature. We also question the validity of the assumption made throughout the literature that demand is exogenous and independent of customers' waiting times. We conclude that the objective functions used in the literature are appropriate only in the case of a central planner facing a demand that is unresponsive to waiting time. For other scenarios, such as a private server facing a demand that does react to waiting time, these objective functions are only shortcuts for the real objective functions that must be used. A more general model is then proposed that fits these scenarios well. Finally, we determine the impact of using the literature's objective functions on optimal appointment policies.     

ROBUSTNESS OF VARIOUS PRODUCTION CONTROL POLICIES IN SEMICONDUCTOR MANUFACTURING

This paper compares several different production control policies in terms of their robustness to random disturbances such as machine failures, demand fluctuations, and system parameter changes. Simulation models based on VLSI wafer fabrication facilities are utilized to test the performance of the policies. Three different criteria, namely, the average total WIP, the average backlog, and a cost function combining these measures, are used to evaluate performance. Among the policies tested, the Two‐Boundary Control policy outperforms the others.     

A FRAMEWORK FOR MACHINE SCHEDULING PROBLEMS WITH CONTROLLABLE PROCESSING TIMES

This is a study of single and parallel machine scheduling problems with controllable processing time for each job. The processing time for job j depends on the position of the job in the schedule and is a function of the number of resource units allocated to its processing. Processing time functions and processing cost functions are allowed to be nonlinear. The scheduling problems considered here have important applications in industry and include many of the existing scheduling models as special cases. For the single machine problem, the objective is minimization of total compression costs plus a scheduling measure. The scheduling measures include makespan, total flow time, total differences in completion times, total differences in waiting times, and total earliness and tardiness with a common due date for all jobs. Except when the total earliness and tardiness measure is involved, each case the problem is solved efficiently. Under an assumption typically satisfied in just-in-time systems, the problem with total earliness and tardiness measure is also solved efficiently. Finally, for a large class of processing time functions; parallel machine problems with total flow time and total earliness and tardiness measures are solved efficiently. In each case we reduce the problem to a transportation problem.     

A BRANCH-AND-BOUND APPROACH FOR SEQUENCING EXPANSION PROJECTS

The paper examines the problem of finding a sequence of a finite set of expansion projects to meet a deterministic demand projection at minimum discounted cost. As the general problem is NP-complete, we focus on the case when the demand growth is in the exponential form, which is quite often found in applications of electric power generation, transportation, water resources and communication. We find that projects' annual costs are an effective ranking criteria for determining an optimal expansion sequence. As the annual cost for a project is a function of time or capacity level, an optimal expansion sequence can be obtained easily if dominance orders of the annual costs exist for all pairwise projects, which is likely to be the case for most practical problems. When the annual costs for the projects are in conditional order, a branch-and-bound algorithm has been developed to effectively reduce the searching range. Our extensive computational results show that the approach is very efficient compared with the other approaches and always solves the problem to optimum although the optimality of the approach still remains to be proven.     

A PAVEMENT MANAGEMENT DECISION SUPPORT SYSTEM

We present a pavement management expert system developed by the University of Wisconsin-Madison and implemented within a geographical information system for the Wisconsin Department of Transportation. The system uses pavement data regularly collected on the state's 12,000 miles of highway to assist engineers, planners, and budget analysts' management decisions about pavements to be included in 6-year improvement and 3-year maintenance programs. The system has a three-layer architecture. The lowest level suggests treatments for each of a large number of small segments of highway. The middle layer aggregates segments, suggests alternative treatments, and estimates the cost of each. The top layer prioritizes the projects and incorporates them into intermediate-range plans. The geographical information system environment enables integration of existing databases within the system using a topologically structured geographic database and specialized software.     

IMPLEMENTING INITIATIVES ON QUALITY: AN INTRODUCTION TO THE SPECIAL ISSUE ON TOTAL QUALITY MANAGEMENT

In the early 1980s, companies around the world, learning from the Japanese experience, saw that they could address their severe competitive problems related to productivity and quality only by looking at the entire set of processes and organizational relationships in the context of the customer's needs. This approach was termed total quality management (TQM). As companies pursue quality-related initiatives, they must deal with a number of issues; some of these issues are addressed here: measurement of benefits, feedback and recognition, work-teams, teaching continuous improvement, and enhancing the effectiveness of statistical process control charts.     

A SINGLE-MACHINE SCHEDULING MODEL WITH FIXED-INTERVAL DELIVERIES

We consider an environment where a production facility modeled as a single machine needs to assign delivery dates to several orders and find a feasible sequence. Tardy jobs are not allowed. The delivery dates are to be at prespecified fixed intervals. The objective is to minimize the due date penalty and the cost of earliness. We provide a dynamic programming-based solution procedure that runs in polynomial time. We develop several dominance results that reduced the computational requirement by an order of magnitude in our computational study.     

INTRODUCTION: SHAPING THE FUTURE OF MANUFACTURING AND SERVICE OPERATIONS

The challenges and opportunities in production and operations management (POM) are almost unlimited because in the world economy, manufacturing andservice operations account for more than 10 trillion dollars per year and in any single industry, the performance varies widely from country to country and from organization to organization. The goal of Production and Operations Management is to contribute to improving the management of manufacturing and service operations all over the world. The editors and reviewers judge the papers published in the journal for their contribution to improving of business practices and to further closeness between research and practice. The journal will publish high quality papers on a broad range of topics in POM, and it encourages all paradigms, old and new. We also invite managers from around the world to describe specific POM problems that provide challenging opportunities for academic research.