On the Limitations of Redundancies in the Improvement of System Reliability

Some program managers share a common belief that adding a redundant component to a system reduces the probability of failure by half. This is true only if the failures of the redundant components are independent events, which is rarely the case. For example, the redundant components may be subjected to the same external loads. There is, however, in general a decrease in the failure probability of the system. Nonetheless, the redundant element comes at a cost, even if it is less than that of developing the first one when both are based on the same design. Identical parts save the most in terms of design costs, but are subjected to common failure modes from possible design errors that limit the effectiveness of the redundancy. In the development of critical systems, managers thus need to decide if the costs of a parallel system are justified by the increase in the system's reliability. NASA, for example, has used redundant spacecraft to increase the chances of mission success, which worked well in the cases of the Viking and Voyager missions. These two successes, however, do not guarantee future ones. We present here a risk analysis framework accounting for dependencies to support the decision to launch at the same time a twin mission of identical spacecraft, given incremental costs and risk-reduction benefits of the second one. We illustrate this analytical approach with the case of the Mars Exploration Rovers launched by NASA in 2003, for which we had performed this assessment in 2001.     

SEX ROLE CONSIDERATIONS AND BEHAVIORAL MARITAL THERAPY: EQUAL DOES NOT MEAN IDENTICAL*

Despite the egalitarian position espoused in behavioral marital therapy, little attention has been paid to sex role issues and female-male differences. This paper explores advantages and disadvantages of behavioral marital therapy vis à vis the treatment of women and men. Features of behavioral marital therapy implicated as important in the consideration of sex role issues include underlying assumptions of egalitarianism, assumptions of external causality, and orientation toward action, as well as specific procedures such as goal setting, behavioral exchange and training in communication and problem-solving skills. Each of these features is evaluated with respect to clinical considerations as well as to research findings on female-male differences in marriage. The paper concludes with recommendations as to how behavioral marital therapy could become more sensitive to sex role issues.     

Some Implications for Management Development of Research into Managers' Moral Dilemmas

In this paper, we present two cases of moral dilemmas as told by the managers who had faced them. We analyse the cases, drawing on frameworks developed by Toffler (1986), Kohlberg (1981) and Maclagan (1990). We also comment on the broader findings of the research from which the cases were taken. These analyses and findings and those of other researchers (e.g. Waters et al., 1986) suggest a number of requisite ‘moral attributes’ for managers and have, we argue, significant implications for the curriculum for ethical education and development for managers and intending managers. One is that case material needs to reflect more strongly the actual experiences of practising managers; another is that there is scope for wider use of experiential methods on management ethics courses. We conclude with a call for a multifaceted approach to ethical education as a lifespan process entailing the development of personal and interpersonal skills and qualities, and self-knowledge as well as cognitive skills. While we acknowledge that ethical education needs to take account of learners' differing levels of prior experience, stages of moral development and levels of learning maturity, our over-riding concern is that learners are prepared for and helped to live through the very ‘real’ dilemmas that they are likely to experience in managerial work.     

News Media and International Negotiation

It is widely recognized that leaks can hamper internationalnegotiations, but the ability of publicity to promote agreementamong nations has received less attention. This article arguesthat the press contributes to international agreement insofaras it illuminates the issues under negotiation, helps to ensureintra-governmental coordination, links governments with interestedpublics, and provides supplementary communication channels fordiplomacy.     

Statistical morphology

This paper first introduces a parametric model for the generation of stationary random correlated binary sequences. The parameters of the model include the probability that a pixel is a binary one pixel and the length of the structuring element which dilates the initially spatially uncorrelated sequence. The spatial statistics of such eroded, dilated, opened and closed correlated binary sequences are derived in terms of the spatial statistics of the input binary sequence. Understanding of such one-dimensional processing is a precondition for understanding what happens in the more interesting two- dimensional case.     

Sensitivity to bodily nonverbal communication as a factor in practitioner-patient rapport

The relationship between physicians' nonverbal sensitivity and the satisfaction of their patients was tested in two field studies. In the first study, 40 physicians were given a film test of nonverbal sensitivity (the PONS test) and were evaluated by their patients. The second study was a replication using 31 additional physicians. Most noteworthy for research in therapeutic interaction, the present studies contained three methodological advances: (1) the use of actual patients' ratings of satisfaction with treatment, (2) the extension of research from psychological to medical settings, and (3) the use of a standardized test of nonverbal decoding skill. Physicians' skill at reading the emotion conveyed through the nonverbal channel of body movement was found to be significantly correlated with their interpersonal success with patients in the clinical setting.The authors would like to thank Donald Dickson, M.D., Mary Ann Spadaro, M.D., Louise M. Prince, John L. Helmuth, Jr., Helene M. Murphy, and the physicians and patients who participated in the research. Study I was supported by a Peter B. Livingston Fellowship from the Massachusetts Mental Health Center and Study II by a W. K. Kellogg Fellowship from the Hospital Research and Educational Trust, both to the senior author.