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Engineering Process (engineering + process)
Selected AbstractsCultivation and engineering of a software metrics programINFORMATION SYSTEMS JOURNAL, Issue 1 2003Jakob Iversen Abstract. This paper reports from a case study of an organization that implements a software metrics program to measure the effects of its improvement efforts. The program measures key indicators of all completed projects and summarizes progress information in a quarterly management report. The implementation turns out to be long and complex, as the organization is confronted with dilemmas based on contradictory demands and value conflicts. The process is interpreted as a combination of a rational engineering process in which a metrics program is constructed and put into use, and an evolutionary cultivation process in which basic values of the software organization are confronted and transformed. The analysis exemplifies the difficulties and challenges that software organizations face when bringing known principles for software metrics programs into practical use. The article discusses the insights gained from the case in six lessons that may be used by Software Process Improvement managers in implementing a successful metrics program. [source] An MDE modeling framework for measurable goal-oriented requirementsINTERNATIONAL JOURNAL OF INTELLIGENT SYSTEMS, Issue 8 2010Fernando Molina It is a proved fact that the appropriate management of requirements is one of the most influential factors in the success of software development projects. With the advent of the model-driven engineering (MDE) development paradigm, the need for formal gathering mechanisms, which provide the necessary degree of nonambiguity and detail, has led to the proposal of a myriad of requirements metamodels. However, a great disparity exists, both in the concepts/relationships and in the underlying semantics involved in each metamodel. Moreover, most existing proposals lack backward (e.g., alignment with business goals) or forward (e.g., connection with validation methods) traceability. In view of this situation, this article proposes a "measurable requirements metamodel" that offers support to the elicitation of measurable requirements. This support is based on the explicit connection of goals, requirements, and measures, thus fostering a goal-driven measurable requirements engineering (RE) perspective. Additionally, since it is well known that metamodels only reflect the abstract syntax of the modeling language, the proposed metamodel also includes a notation (concrete syntax) which, for reasons of understandability, is based on the goal-oriented requirements language (GRL) notation. This notation is supported by a unified modeling language (UML) profile that facilitates its adoption by RE analysts in the context of any UML-based software engineering process. To support this proposal, an Eclipse tool has been developed. This tool permits the integration of measurable requirements as a driving force in the context of a given MDE development process. © 2010 Wiley Periodicals, Inc. [source] The Measure of Performance in Logistics AcquisitionNAVAL ENGINEERS JOURNAL, Issue 4 2000J. A. Elliott-Brown ABSTRACT Acquisition reform initiatives changed the way we buy logistics are bought Structured military standards and regulations were replaced with performance specifications to enable determination up front of the best logistics resources for a system as a function of the systems engineering process. The emphasis is on planning the acquisition to know "what, how, when, where, and why" before the contract is written. The need is to incorporate "guidance" in the contract to eliminate future supportability and sus-tainability issues and problems. The goal is to reduce redundancies in deliv-erables, use and enhance what is available, and to be flexible and innovative in meeting logistics requirements. [source] Size and shape of In rich clusters and InGaN QWs at the nanometer scalePHYSICA STATUS SOLIDI (C) - CURRENT TOPICS IN SOLID STATE PHYSICS, Issue 7 2005P. Ruterana Abstract Following the need to accurately understand the In composition fluctuations and their role on the optical properties of the GaN based heterostructures, an investigation of MOCVD InGaN/GaN quantum wells is carried out. To this end, quantitative High Resolution Transmission Electron Microscopy (HRTEM) is coupled with image simulation and Finite Element Method (FEM) for the thin foil relaxation modelling. The results show that the indium content can reach x = 1 in the clusters inside the core. In these MOCVD QWs, we attempt to connect the Quantum dot density, composition, and shape to the growth conditions, in order to help the engineering process of highly efficient devices. (© 2005 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Empirical design of computer support and staffing in concurrent engineeringHUMAN FACTORS AND ERGONOMICS IN MANUFACTURING & SERVICE INDUSTRIES, Issue 2 2006Joe W. Meredith Manufacturing environments are characterized by underlying operational approaches and assumptions. One such assumption is that concurrent engineering (CE) is superior to traditional sequential processing. A laboratory experiment was conducted using 180 engineering and building construction students as subjects. The engineering methodology variable was sequential and concurrent engineering. There were large teams, consisting of six students, and small teams, consisting of three students. The computer support variable was using and not using groupware. Each team was given a set of requirements to design a transportation system that moved a payload from one point to another. Each team was asked to (a) develop a design concept, (b) develop a detail design in the form of engineering drawings, (c) manufacture the system based on their design products (e.g., drawings and specifications) using toy plastic LEGOS, and (d) test the system to determine if it met the design requirements. There was no significant difference in performance between concurrent engineering groups and sequential engineering processes. Small groups significantly outperformed large groups in all conditions. Computer support did not significantly improve the performance of large or small groups. Participants in the experiment were equally satisfied with all conditions. An external survey strongly endorsed the superiority of CE as compared to sequential engineering. Results are discussed in terms of why practitioners believe in the effectiveness of CE, yet an empirical test failed to demonstrate better performance. © 2006 Wiley Periodicals, Inc. Hum Factors Man 16: 177,193, 2006. [source] An analysis of the effect of a reliability paradigm shift on leading British aerospace companiesQUALITY AND RELIABILITY ENGINEERING INTERNATIONAL, Issue 4 2002J. A. Jones Abstract The aerospace industry is moving towards a new paradigm for the statement of reliability specifications. This paradigm is not a technical metric inherent to a system in isolation, but rather encompasses the wider objectives, operational profile and logistic priorities of its customer. This customer focus is encapsulated in the metrics Failure Free Operating Period and Maintenance Free Operating Period. These metrics describe the duration of effective system operation, in the first case for systems where faults and maintenance are permitted and in the second for systems where faults may not be repaired. As part of the Department of Trade and Industry (DTI) funded Aerospace Project for Insertion of Reliability (ASPIRE) research programme, which itself is part of the Ultra Reliable Aircraft (URA) programme, representatives of leading aerospace companies were interviewed about their opinion n how this new reliability paradigm and associated concepts would affect their way of doing business and their engineering processes. It would appear that the aerospace industry is ready for a move to a more realistic set of reliability metrics and away from the old style MTBF based metrics. This sea change would most likely be welcomed by customers, but as yet the manufacturing companies are unconvinced that such a radical move would be a good thing. Much of the resistance to change is due to old-fashioned, but well entrenched, beliefs in the traditional way of doing things. A move away from this would bring freshness to the industry and lead to cost and time savings as the traditional approach is dropped in favour of a more planned and thought out approach. Copyright © 2002 John Wiley & Sons, Ltd. [source] Self-sustained oscillations in opposed impinging jets in an enclosureTHE CANADIAN JOURNAL OF CHEMICAL ENGINEERING, Issue 5 2000David A. Johnson Abstract The flow of jets in confining enclosures has significant application in many engineering processes. In particular, the impingement of axisymmetric jets in a confined space has been examined using flow visualization, laser Doppler anemometry, and numerical simulations. Several flow regions were found; stable steady, regular oscillatory, and irregular oscillatory. Initially, a steady flow field existed for all arrangements for Red < ,90 (based on the nozzle diameter d, the fluid kinematic viscosity v and the volumetric flow rate Q through the nozzle (Q = ,d2/4Uavg)) but subsequent increments in the fluid velocity caused a regularly oscillating flow field to emerge. The onset of the oscillations and the upper limit of finite oscillations were found to be a function of the Red, and the nozzle diameter to chamber dimension ratio. Steady numerical simulations predicted the steady flow field well and good agreement was obtained in unsteady simulations of the oscillating flow field. The oscillating flow field is considered to be a class of self-sustaining oscillations where instabilities in the jet shear layer are amplified because of feed back from pressure disturbances in the impingement region. L'écoulement de jets dans des espaces confinés a des applications importantes dans de nombreux precédés d'ingénierie. On a examiné en particulier la collision de jets axisymétriques dans un espace confiné au moyen de la visualisation des écoulements, de l'anémométrie par laser Doppler et de simulations numériques. On a trouvé plusieurs régions d'écoulement : stable-stationnaire, régulier-oscillatoire et irrégulier-oscillatoire. Initialement, il existe un champ d'écoulement stationnaire pour toutes les configurations lorsque Red < ,90 (basé sur le diamètre de tuyère d, la viscosité cinématique du fluide (et le débit volumétrique Q dans la tuyère (Q = ,d24Uavg)); mais une augmentation subséquente de la vitesse du fluide déclenche un champ d'écoulement oscillatoire régulier. On a trouvé que l'apparition des oscillations et la limite supérieure des oscillations finies sont fonction de Red et du rapport entre le diamètre de l'orifice et la dimension de la chambre. Des simulations numériques stationnaires prédisent bien le champ d'écoulement stationnaire et un bon accord est obtenu pour des simulations non stationnaires du champ d'écoulement oscillant. Le champ d'écoulement oscillant est considéré être une catégorie d'oscillations qui se maintiennent seules dans laquelle les instabilités dans la couche de cisaillement des jets sont amplifiés par un effet retour des perturbations de pression dans la région de collision. [source] Review: Biodegradation of tributyltins (organotins) by marine bacteriaAPPLIED ORGANOMETALLIC CHEMISTRY, Issue 1 2003S. K. Dubey Abstract Many marine bacterial strains have an inherent capability to degrade toxic organotin compounds, especially tributyltins (TBTs), that enter into the environment in the form of insecticides, fungicides and antifouling paints as a result of anthropogenic and industrial activities. Significant degradation of these compounds in the ambient environment may take several years, and it is necessary to consider methods or strategies that can accelerate the degradation process. There have been few demonstrations of biological degradation of these organotin biocides exclusively in laboratory-scale experiments. Compared with the few bench-scale degradation processes, there are no reports of field-scale processes for TBT bioremediation, in spite of its serious environmental threat to non-target organisms in the aquatic environment. Implementation of field-scale biodegradation of TBT requires inputs from biology, hydrology, geology, chemistry and civil engineering. A framework is emerging that can be adapted to develop new processes for bioremediation of toxic environmental wastes. In the case of TBT bioremediation, this framework incorporates screening and identification of natural bacterial strains, determination of optimal conditions for growth of isolates and TBT degradation, establishment of new metabolic pathways involved in TBT degradation, identification, localization and cloning of genes involved in degradation and in TBT resistance, development of suitable microbial strains using genetic manipulation techniques for practical applications and optimization of practical engineering processes for bioremediation of organotin-contaminated sites. The present review mainly addresses the aspect of TBT biodegradation with special reference to environmental sources of TBT, chemical structure and biological activity, resistant and degrading bacterial strains, possible mechanisms of resistance and degradation and the genetic and biochemical basis of TBT degradation and resistance. It also evaluates the feasibility and potential of natural and genetically modified TBT-degrading bacterial strains in field-scale experiments to bioremediate TBT-contaminated marine sites, and makes recommendations for more intensive and focused research in the area of TBT bioremediation mediated by marine bacterial strains. Copyright © 2002 John Wiley & Sons, Ltd. [source] | ||||||||||||||||