Simultaneous optimization of mechanical properties of steel by maximizing exponential desirability functions

A modelling approach to optimize a multiresponse system is presented. The approach aims to identify the setting of the input variables to maximize the degree of overall satisfaction with respect to all the responses. An exponential desirability functional form is suggested to simplify the desirability function assessment process. The approach proposed does not require any assumptions regarding the form or degree of the estimated response models and is robust to the potential dependences between response variables. It also takes into consideration the difference in the predictive ability as well as relative priority among the response variables. Properties of the approach are revealed via two real examples—one classical example taken from the literature and another that the authors have encountered in the steel industry.     

Employee performance management across borders: A review of relevant academic literature

The purpose of this paper is to survey the emerging academic literature on employee performance management (PM) from an international perspective. The primary information source was a search of electronic databases. Two criteria were used to determine which studies to include in the literature survey: (1) those published in an English-language blind refereed academic journal, and (2) those focused on employee PM or performance appraisal (PA) from an international/global perspective. Sixty-four articles, published between 1985 and 2005, met the criteria. A preliminary scheme was developed for classifying the existing academic research into conceptual and empirical articles. The empirical articles were further classified by their foci and themes. In addition to classifying the articles, the paper presents a summary of what can be learned from the major findings of the empirical studies. The major conclusion is that the academic literature on cross-border PM is relatively atheoretical and exploratory in nature and that the design and substance of the research studies are weak. With regard to themes, there are a number of foci in the literature with only scant attention paid to the central concern with the PM of expatriates as expressed by firms. The empirical articles look at the disparate components of PA and are interested mainly in cultural differences as an intervening variable. Several recommendations are presented for researchers to help focus future research on cross-border PM.     

A GRAPHICAL DIAGNOSTIC FOR VARIANCE FUNCTIONS

This paper proposes diagnostic plots for regression variance functions. It shows how to extend graphical methodology that uses Bayesian sampling for checking the regression mean function to also check the variance function. Plots can be constructed quickly and easily for any model of interest. These plots help to identify model weaknesses and can suggest ways to make improvements. The proposed methodology is illustrated with two examples: a simple linear regression model to fix ideas, and a more complex study involving count data to demonstrate the potential for wide application.     

An optimality criterion for supersaturated designs with quantitative factors

A supersaturated design (SSD) is a factorial design in which the degrees of freedom for all its main effects exceed the total number of distinct factorial level-combinations (runs) of the design. Designs with quantitative factors, in which level permutation within one or more factors could result in different geometrical structures, are very different from designs with nominal ones which have been treated as traditional designs. In this paper, a new criterion is proposed for SSDs with quantitative factors. Comparison and analysis for this new criterion are made. It is shown that the proposed criterion has a high efficiency in discriminating geometrically nonisomorphic designs and an advantage in computation.     

Special Invited Paper: Dimension Reduction and Visualization in Discriminant Analysis (with discussion)

This paper discusses visualization methods for discriminant analysis. It does not address numerical methods for classification per se, but rather focuses on graphical methods that can be viewed as pre-processors, aiding the analyst's understanding of the data and the choice of a final classifier. The methods are adaptations of recent results in dimension reduction for regression, including sliced inverse regression and sliced average variance estimation. A permutation test is suggested as a means of determining dimension, and examples are given throughout the discussion.     

Bayesian D-optimal supersaturated designs

We introduce a new class of supersaturated designs using Bayesian D-optimality. The designs generated using this approach can have arbitrary sample sizes, can have any number of blocks of any size, and can incorporate categorical factors with more than two levels. In side by side diagnostic comparisons based on the E(s²)$E(s^2)$ criterion for two-level experiments having even sample size, our designs either match or out-perform the best designs published to date. The generality of the method is illustrated with quality improvement experiment with 15 runs and 20 factors in 3 blocks.     

Personality and Perceived Business Values: Synergistic Effects for the Myers–Briggs Type Indicator and Management Ratings

This paper identified additive and synergistic effects of personality for management ratings of business values. Results were discussed in terms of theoretical implications for the MBTI and type theory as well as implications for management within business organizations. There appears to be a natural affinity (and antipathy) between some personality types or forms and certain business values. This revised version was published online in July 2006 with corrections to the Cover Date.     

Impact of Absenteeism on Assembly Line Quality and Throughput

Assembly lines function best when every worker is present. When a worker is absent, management must scramble to quickly find a replacement. Usually, the replacement will not be as proficient as the absent worker. This can reduce quality and throughput. We present two assembly line work‐systems models (one for lines with Andon and one for lines without Andon) that show one mechanism whereby absenteeism could impact quality and throughput. We exercise these models to provide insights into absenteeism's impact on quality and throughput. While the paper is written in the concrete terms of automotive assembly, the concepts and results apply to manual assembly lines in general.