Implementation issues in product line scoping

Often product line engineering is treated similar to the waterfall model in traditional software engineering, i.e., the different phases (scoping, analysis, architecting, implementation) are treated as if they could be clearly separated and would follow each other in an ordered fashion. However, in practice strong interactions between the individual phases become apparent. In particular, how implementation is done has a strong impact on economic aspects of the project and thus how to adequately plan it. Hence, assessing these relationships adequately in the beginning has a strong impact on performing a product line project right. In this paper we present a framework that helps in exactly this task. It captures on an abstract level the relationships between scoping information and implementation aspects and thus allows to provide rough guidance on implementation aspects of the project. We will also discuss the application of our framework to a specific industrial project

Measurement of the Charged Multiplicities in b, c and Light Quark Events from Z0 Decays

Average charged multiplicities have been measured separately in $b$, $c$ and light quark ($u,d,s$) events from $Z^0$ decays measured in the SLD experiment. Impact parameters of charged tracks were used to select enriched samples of $b$ and light quark events, and reconstructed charmed mesons were used to select $c$ quark events. We measured the charged multiplicities: $\bar{n}_{uds} = 20.21 \pm 0.10 (\rm{stat.})\pm 0.22(\rm{syst.})$, $\bar{n}_{c} = 21.28 \pm 0.46(\rm{stat.}) ^{+0.41}_{-0.36}(\rm{syst.})$ $\bar{n}_{b} = 23.14 \pm 0.10(\rm{stat.}) ^{+0.38}_{-0.37}(\rm{syst.})$, from which we derived the differences between the total average charged multiplicities of $c$ or $b$ quark events and light quark events: $\Delta \bar{n}_c = 1.07 \pm 0.47(\rm{stat.})^{+0.36}_{-0.30}(\rm{syst.})$ and $\Delta \bar{n}_b = 2.93 \pm 0.14(\rm{stat.})^{+0.30}_{-0.29}(\rm{syst.})$. We compared these measurements with those at lower center-of-mass energies and with perturbative QCD predictions. These combined results are in agreement with the QCD expectations and disfavor the hypothesis of flavor-independent fragmentation.Comment: 19 pages LaTex, 4 EPS figures, to appear in Physics Letters

Lernen von abkuerzungsorientiertem diagnostischen Problemloesen

Available from TIB Hannover: RO7718(91-05) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman

Fallbasiertes Problemloesen in Expertensystemen Begriffliche und inhaltliche Betrachtungen

For the field of expert systems, case-based problem solving is a hot research topic. Since it is within the focus of different fields of research there are many different views on this approach. In this paper, we want to go a first step towards the development of a simple framework which enables the comparison of different systems and approaches. We give an overview of the current state of the art based on an exemplary selection of approaches to case-based diagnosis. Finally we point out some open questions and interesting research goalsIm Bereich der Expertensysteme ist das Problemloesen auf der Basis von Fallbeispielen ein derzeit sehr aktuelles Thema. Da sich sehr unterschiedliche Fachgebiete und Disziplinen hiermit auseinandersetzen, existiert allerdings eine entsprechende Vielfalt an Begriffen und Sichten auf fallbasiertes Problemloesen. In diesem Beitrag werden wir einige fuer das fallbasierte Problemloesen wichtige Begriffe praezisieren bzw. begriffliche Zusammenhaenge aufdecken. Die dabei verfolgte Leitline ist weniger die, ein vollstaendiges Begriffsgebaeude zu entwickeln, sondern einen ersten Schritt in Richtung eines einfachen Beschreibungsrahmens zu gehen, um damit den Vergleich verschiedener Ansaetze und Systeme zu ermoeglichen. Auf dieser Basis wird dann der derzeitige Stand der Forschung am Beispiel konkreter Systeme zur fallbasierten Diagnose dargelegt. Den Abschluss bildet eine Darstellung bislang offener Fragen und interessanter ForschungszieleSIGLEAvailable from TIB Hannover: RO 7718(91-03) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekDEGerman

Die Lernkomponente der MOLTKE_3-Werkbank zur Diagnose technischer Systeme

Available from TIB Hannover: RO 7718(90-08) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman

CBR-PEB: an application implementing reuse concepts of the experience factory for the transfer of CBR system know-how

An Experience Factory is an infrastructure for organizational learning in software development that includes an Experience Base as an organizational memory. We introduce a system architecture showing how such an infrastructure can be technically supported based on Case-Based Reasoning (CBR) technology. As a first instantiation of this architecture, we present the CBR-PEB application, a publicly accessible WWW-based experience base about CBR applications and tools. (orig.)Accepted for publication in the proceedings of the 7th German workshop on case-Based ReasoningSIGLEAvailable from TIB Hannover: RR 9594(98-58/E) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekDEGerman

Applications of knowledge acquisition in experimental software engineering

Many tasks in experimental software engineering (ESE) involve the acquisition of knowledge. Only for very few of them have systematic knowledge acquisition (KA) practices been established. It is expected that these ESE tasks can be accomplished more effectively if the application of appropriate systematic KA methods is fostered. Most reports of KA applications in software engineering address only some selected aspects. A broader ESE perspective with its additional facets (e.g., quality and knowledge management issues) has not yet been presented so far. This paper surveys applications of knowledge acquisition in experimental software engineering, introduces a repository of knowledge elicitation (KEL) techniques, and suggests a methodology for the development of customised KA methods in experimental software engineering. Repository and methodology aim at fostering the dissemination of systematic KA practices in ESE. They are applied at Fraunhofer IESE to develop methods for the acquisition of experimental software engineering knowledge. (orig.)Available from TIB Hannover: RR 9594(98-59/E) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman

Ein System zur fallbasierten Wissensverarbeitung in technischen Diagnosesystemen

Available from TIB Hannover: RO 7718(90-07) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman

Improving organizational memories through user feedback

The benefits of an organizational memory are ultimately determined by the usefulness of the organizational memory as perceived by its users. Therefore, an improvement of an organizational memory should be measured in the added perceived usefulness. Unfortunately, the perceived usefulness has many impact factors (e.g., the precision of the user query, the urgency with which the user needs information, the coverage of the underlying knowledge base, the quality of the schema used to store knowledge, and the quality of the implementation). Hence, it is difficult to identify good starting points for improvement. This paper presents the goal-oriented method OMI (Organizational Memory Improvement) for improving an organizational memory incrementally from the user's point of view. It has been developed through several case studies and consists of a general usage model, a set of indicators for improvement potential, and a cause-effect model. At each step of the general usage model of OMI, protocol cases are recorded to pinpoint improvement potential for increasing the perceived usefulness. If improvement potential is identified based on the interpretation of the protocol cases, the user is asked for specific improvement suggestions. Since this is a continuous diagnosis of the usefulness of the organizational memory, this method is able to adapt the organizational memory to the needs of the users - even if the environment, for which the organizational memory was designed, changes. (orig.)SIGLEAvailable from TIB Hannover: RR 9594(99-4/E) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekDEGerman