Modeling and Managing the Percentage of Satisfied Customers in Hidden and Revealed Waiting Line Systems

We perform an analysis of various queueing systems with an emphasis on estimating a single performance metric. This metric is defined to be the percentage of customers whose actual waiting time was less than their individual waiting time threshold. We label this metric the Percentage of Satisfied Customers (PSC.) This threshold is a reflection of the customers' expectation of a reasonable waiting time in the system given its current state. Cases in which no system state information is available to the customer are referred to as “hidden queues.” For such systems, the waiting time threshold is independent of the length of the waiting line, and it is randomly drawn from a distribution of threshold values for the customer population. The literature generally assumes that such thresholds are exponentially distributed. For these cases, we derive closed form expressions for our performance metric for a variety of possible service time distributions. We also relax this assumption for cases where service times are exponential and derive closed form results for a large class of threshold distributions. We analyze such queues for both single and multi‐server systems. We refer to cases in which customers may observe the length of the line as “revealed” queues.“ We perform a parallel analysis for both single and multi‐server revealed queues. The chief distinction is that for these cases, customers may develop threshold values that are dependent upon the number of customers in the system upon their arrival. The new perspective this paper brings to the modeling of the performance of waiting line systems allows us to rethink and suggest ways to enhance the effectiveness of various managerial options for improving the service quality and customer satisfaction of waiting line systems. We conclude with many useful insights on ways to improve customer satisfaction in waiting line situations that follow directly from our analysis.     

Using the End‐User Computing Satisfaction (EUCS) Instrument to Measure Satisfaction with a Web Site

The purpose of this study is to revise and revalidate the End‐User Computing Satisfaction (EUCS) instrument to measure satisfaction with a Web site from a usability perspective. This study is especially important given the increased significance of the Web and the uniqueness of the Web as a computing environment. A total of 176 students participated in a lab simulation that involved a usability evaluation of the Lands' End Web site ( http://www.landsend.com ). Students were asked to complete a set of tasks, record their answers, and then complete the EUCS instrument. Confirmatory factor analysis and invariance analyses were conducted to test the reliability, validity, and generalizability of the revised EUCS. The results show that the EUCS is a valid and robust instrument in the Web environment but that one of the subfactors, timeliness, will need further refinement in the future. Usability practitioners can use the EUCS to measure end‐user satisfaction with a Web site and use the feedback for improving Web‐site design. We describe a case study of an actual usability application that utilized the revised EUCS effectively to support the design of building supply Web sites involving two types of end users, homeowners and contractors. We also propose a typology that researchers can use as a starting point to judge when it is necessary to revalidate an instrument like the EUCS. Finally, we discuss the limitations of our study and present avenues for future research.     

National Differences in the Diffusion and Design of Technological Innovation: The Role of Inter-Organizational Networks

This paper reports results from a study of the design and diffusion of computer-aided production management (CAPM) technologies across four European countries (UK, France, The Netherlands and Sweden). The study combined surveys of members of professional operations management associations in each of these four countries and interviews with operations managers and technology suppliers (software suppliers and consultants). The findings revealed significant differences across countries in the design and diffusion of CAPM. For example, in the UK and France highly objectified 'best practice' technologies, supported by standardized software, had diffused more widely than in Sweden and The Netherlands, where solutions tended to be developed in-house and customized to the local context. This paper explains these findings in terms of differences in the structure and operation of these four professional association networks. These differences in inter-organizational networking encouraged different types of knowledge-sharing related to the design of CAPM in the four countries.     

ROBUST ESTIMATION OF SMALL‐AREA MEANS AND QUANTILES

Small‐area estimation techniques have typically relied on plug‐in estimation based on models containing random area effects. More recently, regression M‐quantiles have been suggested for this purpose, thus avoiding conventional Gaussian assumptions, as well as problems associated with the specification of random effects. However, the plug‐in M‐quantile estimator for the small‐area mean can be shown to be the expected value of this mean with respect to a generally biased estimator of the small‐area cumulative distribution function of the characteristic of interest. To correct this problem, we propose a general framework for robust small‐area estimation, based on representing a small‐area estimator as a functional of a predictor of this small‐area cumulative distribution function. Key advantages of this framework are that it naturally leads to integrated estimation of small‐area means and quantiles and is not restricted to M‐quantile models. We also discuss mean squared error estimation for the resulting estimators, and demonstrate the advantages of our approach through model‐based and design‐based simulations, with the latter using economic data collected in an Australian farm survey.     

Reports of Conferences, Institutes, and Seminars

Reports on the 2005 North Carolina Serials Conference, the twentieth anniversary conference of the North American Serials Interest Group, the 2005 Acquisitions Institute at Timberline Lodge, and a program on electronic archiving sponsored by the New England Chapter of the Association of College and Research Libraries.     

钓鱼岛问题的历史与现状

钓鱼岛问题,是历史遗留在中日之间的领土主权归属问题。钓鱼岛自古以来就是中国领土,日本对钓鱼岛的实际占领,以及日方在钓鱼岛问题上所持的强硬立场,使钓鱼岛问题日益复杂化,已成为中日关系中最为敏感的问题之一。它不仅关系到中日关系的发展,而且涉及亚太地区战略格局发展的大局。中日必须从21世纪两国关系发展大局出发,妥善处理分歧,和平解决争端。      

The structure of employee attitudes to safety: A European example

This paper concerns organizational safety culture and the structure or architecture of employee attitudes to safety as part of that culture. It begins by reviewing the somewhat scant literature relevant to this area, and then reports a study, conducted in a European company, which collected and factor analysed data on employee attitudes to safety. The framework provided for the study was that offered by Purdham (1984), and the results suggested that employees' attitudes to safety, within this company (across occupation/occupational level and country), could be mapped By five orthogonal factors: personal scepticism, individual responsibility, the safeness of the work environment, the effectiveness of arrangements for safety, and personal immunity. The theoretical and practical implications of these findings are discussed, and attention is drawn to their subsequent use in an intervention to enhance safety culture within the organization by attacking supervisors' attitudes to safety.     

Developing the DSM-IV-DSM-IV Criteria to Identify Adolescent Problem Gambling in Non-Clinical Populations

This paper presents a revised version of DSM-IV-J criteria for youth, the DSM-IV-MR-J, together with psychometric data stemming from its use in a major prevalence study of adolescent gambling and problem gambling. The case is made for further development and testing of current and emerging instruments to screen for problem gambling in youth, with the aim of establishing one internationally accepted gold standard measure.     

Parenting Assessment in a Psychiatric Mother and Baby Unit

Correspondence to Dr Gertrude Seneviratne, Section of Perinatal Psychiatry, Division of Psychological Medicine, Institute of Psychiatry, De Crespigny Park, London SE5 8AF, UK. E-mail: G.Seneviratne{at}iop.kcl.ac.uk Summary Courts and social services often seek the advice of mental healthprofessionals in deciding whether a mentally ill mother shouldremain the primary carer of her infant. This paper describesthe referral pathways, outcomes at discharge and subsequently,of a sample of mothers referred for parenting assessments toa psychiatric Mother and Baby Unit. A further aim was to examinefactors predicting outcome. A casenote study of sixty-one consecutivereferrals for in-patient parenting assessment over a six-yearperiod is described. Social Services were contacted to establishdevelopments at least nine months after discharge. Fewer thanhalf of the mothers were discharged together with their babiesat the end of the assessment period, and at follow-up, lessthan a third were still caring for their children. Diagnosisof the mother's illness was the main factor determining whethershe continued to care for her child both at discharge and atfollow-up; mothers with depression were more likely to remainprimary carers. Variations in the timing and process of referralsrelated to a lack of antenatal planning were associated withincreased rates of separation of mother and infant before theassessment. The findings illustrate the need for more integratedco-ordination between professionals in mental health and children'sservices to ensure early planning for mothers and infants atrisk.