Managing design variety, process variety and engineering change: a case study of two capital good firms

Many capital good firms deliver products that are not strictly one-off, but instead share a certain degree of similarity with other deliveries. In the delivery of the product, they aim to balance stability and variety in their product design and processes. The issue of engineering change plays an important in how they manage to do so. Our aim is to gain more understanding into how capital good firms manage engineering change, design variety and process variety, and into the role of the product delivery strategies they thereby use. Product delivery strategies are defined as the type of engineering work that is done independent of an order and the specification freedom the customer has in the remaining part of the design. Based on the within-case and cross-case analysis of two capital good firms several mechanisms for managing engineering change, design variety and process variety are distilled. It was found that there exist different ways of (1) managing generic design information, (2) isolating large engineering changes, (3) managing process variety, (4) designing and executing engineering change processes. Together with different product delivery strategies these mechanisms can be placed within an archetypes framework of engineering change management. On one side of the spectrum capital good firms operate according to open product delivery strategies, have some practices in place to investigate design reuse potential, isolate discontinuous engineering changes into the first deliveries of the product, employ ‘probe and learn’ process management principles in order to allow evolving insights to be accurately executed and have informal engineering change processes. On the other side of the spectrum capital good firms operate according to a closed product delivery strategy, focus on prevention of engineering changes based on design standards, need no isolation mechanisms for discontinuous engineering changes, have formal process management practices in place and make use of closed and formal engineering change procedures. The framework should help managers to (1) analyze existing configurations of product delivery strategies, product and process designs and engineering change management and (2) reconfigure any of these elements according to a ‘misfit’ derived from the framework. Since this is one of the few in-depth empirical studies into engineering change management in the capital good sector, our work adds to the understanding on the various ways in which engineering change can be dealt with.     

Verfügbarkeit von Metallrohstoffen für die Dünnschicht‐Photovoltaik

Availability of raw materials for the thin‐film photovoltaic on the example of gallium, indium and tellurium Gallium, tellurium, and indium are essential components used in the thinfilm technology which are predicted a growing demand. Their occurrence in the earth's crust is comparatively scarce thus they are produced and technically applied in small quantities. The trace metals are produced as a by‐product during extraction and refining of bulk metals such as aluminium, copper, or zinc. Essentially, the mining, processing and refining of the carrier element determines the maximum available production capacity. The global processing capacities of by‐products are limited, and the potentials of extraction are not fully utilized by current methods. Increasing the production of the by‐products would be achieved by increasing the production of the carrier elements or by extending the extraction capacities within an established production route. Moreover, the supply could be enhanced by processing currently untreated ores and concentrates as well as by treating residues from mining and processing.     

The risk of being shot at: Stress, cortisol secretion, and their impact on memory and perceived learning during reality-based practice for armed officers.

A field experiment was organized during a handgun shooting workshop for armed officers (N = 36). In-depth stress analyses involved anticipatory distress, subjective stress, and salivary cortisol reactivity triggered by reality-based handgun shooting practice and, more specifically, by being in an uncontrollable situation with the risk of being shot at. Subsequently, the study examined to what extent exposure to reality-based stress affected working memory performances and self-perceived active learning. As expected, the risk of being shot at caused more anticipatory distress, subjective stress, and increasingly triggered cortisol secretion. Further results showed that, although stress endurance deteriorated working memory performance, participants in the high-realism group simultaneously self-perceivably learned more (i.e., acquired task-relevant skills and competencies). The dual stress effect may result from the professional appreciation of reality-based practice and increased self-efficacy toward hazardous real-life situations. Balancing the intersection between occupational psychology, cognitive psychology, and psychoneuroendocrinology, this study performed stress research in an important and rarely accessible professional setting. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Short communication: A study of Lactobacillus isolates' adherence to and influence on membrane integrity of human Caco-2 cells

The selection criteria of ideal probiotic bacteria are complex and involve many factors. One key criterion is based on the ability of the probiotic bacteria to adhere to the epithelial lining of the gastrointestinal tract. The objective of this study was to evaluate and compare the adherence and influence on membrane integrity of 2 selected lactobacilli isolates—Lactobacillus rhamnosus MI13 (dairy food origin) and L. plantarum RC2 (bovine rumen origin)—to Caco-2 cells in the presence and absence of Escherichia coli. The adhesion and influence on membrane integrity properties of the 2 Lactobacillus isolates were compared with Escherichia coli, a human commensal bacterium. From the adhesion studies, we concluded that the bovine rumen isolate exhibited better adherence to Caco-2 cells than the dairy food isolate. In contrast, the dairy food isolate better protected the Caco-2 monolayer from damage induced by ethanol.     

Targeted disruption of the mouse beta1-adrenergic receptor gene: developmental and cardiovascular effects

At least three distinct beta-adrenergic receptor (beta-AR) subtypes exist in mammals. These receptors modulate a wide variety of processes, from development and behavior, to cardiac function, metabolism, and smooth muscle tone. To understand the roles that individual beta-AR subtypes play in these processes, we have used the technique of gene targeting to create homozygous beta 1-AR null mutants (beta 1-AR -/-) in mice. The majority of beta 1-AR -/- mice die prenatally, and the penetrance of lethality shows strain dependence. Beta l-AR -/- mice that do survive to adulthood appear normal, but lack the chronotropic and inotropic responses seen in wild-type mice when beta-AR agonists such as isoproterenol are administered. Moreover, this lack of responsiveness is accompanied by markedly reduced stimulation of adenylate cyclase in cardiac membranes from beta 1-AR -/- mice. These findings occur despite persistent cardiac beta 2-AR expression, demonstrating the importance of beta 1-ARs for proper mouse development and cardiac function, while highlighting functional differences between beta-AR subtypes.     

Knowledge-Based configuration of image segmentation processes

The solution of an image interpretation problem using digital image analysis methods requires the configuration of an image analysis system to meet the requirements of this specific task the specific data material. This process includes the selection of the appropriate sequence of operators and the adaptation of the free parameters. A system has been developed and is described, which performs this configuration process automatically on the basis of a user-specified task definition, and general knowledge of an image analysis expert. The latter knowledge has been assessed, stored, and used by employing different paradigms of knowledge representation similar to expert systems.     

Backward sensory preconditioning.

In Experiments 1 and 2, rats received initial training in which two neutral events were presented as a serial compound (A?→?X). Subsequent training with A as a signal for shock was found to endow X with the ability to evoke the conditioned response of suppression. Experiment 2 also showed that responding to X was diminished if, prior to testing, Stimulus A underwent extinction. Two possible mechanisms for these findings are considered: (a) that X elicits responding through the associative chain X-A-shock, and (b) that A activates a representation of X that gains direct associative strength during conditioning with A and loses it during extinction of A. Experiment 3 demonstrated that an X-shock association established after initial A?→?X training can be extinguished by nonreinforced presentations of A. These results suggest that associatively evoked representations of stimuli can enter into associations. (PsycINFO Database Record (c) 2010 APA, all rights reserved)