05 Fakultät Informatik, Elektrotechnik und Informationstechnik
Permanent URI for this collectionhttps://elib.uni-stuttgart.de/handle/11682/6
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Item Open Access Mining Java packages for developer profiles : an exploratory study(2017) Ramadani, Jasmin; Wagner, StefanItem Open Access Languages, methods, and tools for software specification(1989) Ludewig, JochenSpecification systems consist of methods, languages, and tools; the languages may be more or less formal. In this paper, the general ideas of semi-formal specification systems are presented, and some examples are shown.Item Open Access Scrum for cyber-physical systems: a process proposal(2014) Wagner, StefanAgile development processes and especially Scrum are chang- ing the state of the practice in software development. Many companies in the classical IT sector have adopted them to successfully tackle various challenges from the rapidly changing environments and increasingly complex software systems. Companies developing software for embedded or cyber-physical systems, however, are still hesitant to adopt such processes. Despite successful applications of Scrum and other agile methods for cyber-physical systems, there is still no complete process that maps their specific challenges to practices in Scrum. We propose to fill this gap by treating all design artefacts in such a development in the same way: In software development, the final design is already the product, in hardware and mechanics it is the starting point of production. We sketch the Scrum extension Scrum CPS by showing how Scrum could be used to develop all design artefacts for a cyber physical system. Hardware and mechanical parts that might not be available yet are simulated. With this approach, we can directly and iteratively build the final software and produce detailed models for the hardware and mechanics production in parallel. We plan to further detail Scrum CPS and apply it first in a series of student projects to gather more experience before testing it in an industrial case study.Item Open Access CASE - eine kritische Übersicht(1989) Ludewig, JochenCASE ist aus dem Bedürfnis entstanden, den Prozeß der Software-Entwicklung durch Werkzeuge so zu unterstützen, daß die Produktivität gesteigert und die Qualität erhöht wird. Solche Werkzeuge sind auf der Basis moderner Rechner und Betriebssysteme möglich. Für die Interessenten ist es allerdings nicht leicht, die seriösen Produktinformationen von den überzogenen Werbesprüchen zu unterscheiden. Der Beitrag zielt zunächst darauf ab, das Wort CASE mit einem klaren Begriff zu verbinden. Der Zusammenhang zwischen Werkzeugen und Methoden wird ausführlich diskutiert. Weitere Schwerpunkte sind eine Übersicht der Werkzeuge, die unter den Begriff CASE fallen, eine Zusammenstellung der wichtigsten Anforderungen, eine Klassifikation von Werkzeugausstattungen und eine Diskussion ungelöster Probleme heutiger Werkzeuge. Einige Prognosen für die zukünftige Entwicklung des Software Engineerings schließen den Vortrag ab.Item Open Access The Quamoco product quality modelling and assessment approach(2012) Wagner, Stefan; Lochmann, Klaus; Heinemann, Lars; Kläs, Michael; Trendowicz, Adam; Plösch, Reinhold; Seidl, Andreas; Goeb, Andreas; Streit, JonathanPublished software quality models either provide abstract quality attributes or concrete quality assessments. There are no models that seamlessly integrate both aspects. In the project Quamoco, we built a comprehensive approach with the aim to close this gap. For this, we developed in several iterations a meta quality model specifying general concepts, a quality base model covering the most important quality factors and a quality assessment approach. The meta model introduces the new concept of a product factor, which bridges the gap between concrete measurements and abstract quality aspects. Product factors have measures and instruments to operationalise quality by measurements from manual inspection and tool analysis. The base model uses the ISO 25010 quality attributes, which we refine by 200 factors and 600 measures for Java and C# systems. We found in several empirical validations that the assessment results fit to the expectations of experts for the corresponding systems. The empirical analyses also showed that several of the correlations are statistically significant and that the maintainability part of the base model has the highest correlation, which fits to the fact that this part is the most comprehensive. Although we still see room for extending and improving the base model, it shows a high correspondence with expert opinions and hence is able to form the basis for repeatable and understandable quality assessments in practice.Item Open Access XSTAMPP: An eXtensible STAMP platform as tool support for safety engineering(2015) Abdulkhaleq, Asim; Wagner, StefanSTPA (Systems-Theoretic Processes Analysis) is a new hazard analysis technique based on STAMP. STPA is already being used in different industrial domains (e.g. space, aviation, medical or automotive). To support the application of STPA and make using STPA more efficient, we developed an open tool called A-STPA. However, the current usage of ASTPA by safety analysts in different areas shows a number of shortcomings in terms of documenting unsafe control actions, drawing different levels of control structure diagrams, documenting the causal factors in STPA Step 2 and supporting the application of STPA in different areas. In this paper, we present an extensible STAMP platform called XSTAMPP as tool support designed specifically to serve the widespread adoption and use of STPA in different areas, to facilitate STPA application to different systems and to be easily extended to include different requirements and features. Moreover, XSTAMPP has the potential to be extended in the future to support the application of CAST for accident analysis. We believe that XSTAMPP is a useful first step toward establishing a base platform to support the application of STAMP methodologies in different domains.Item Open Access Mining valence, arousal, and dominance - possibilities for detecting burnout and productivity?(2016) Mäntylä, Mika; Adams, Bram; Destefanis, Giuseppe; Graziotin, Daniel; Ortu, MarcoSimilar to other industries, the software engineering domain is plagued by psychological diseases such as burnout, which lead developers to lose interest, exhibit lower activity and/or feel powerless. Prevention is essential for such diseases, which in turn requires early identification of symptoms. The emotional dimensions of Valence, Arousal and Dominance (VAD) are able to derive a person's interest (attraction), level of activation and perceived level of control for a particular situation from textual communication, such as emails. As an initial step towards identifying symptoms of productivity loss in software engineering, this paper explores the VAD metrics and their properties on 700,000 Jira issue reports containing over 2,000,000 comments, since issue reports keep track of a developer's progress on addressing bugs or new features. Using a general-purpose lexicon of 14,000 English words with known VAD scores, our results show that issue reports of different type (e.g., Feature Request vs. Bug) have a fair variation of Valence, while increase in issue priority (e.g., from Minor to Critical) typically increases Arousal. Furthermore, we show that as an issue's resolution time increases, so does the arousal of the individual the issue is assigned to. Finally, the resolution of an issue increases valence, especially for the issue Reporter and for quickly addressed issues. The existence of such relations between VAD and issue report activities shows promise that text mining in the future could offer an alternative way for work health assessment surveys.Item Open Access Towards applying a safety analysis and verification method based on STPA to agile software development(2016) Wang, Yang; Wagner, StefanThis paper presents a novel agile process model "S-Scrum" based on the existing development process "Safe Scrum" and extended by a safety analysis method and a safety verification approach based on STPA (System-Theoretic Process Analysis).Item Open Access Alte und neue Sprachkonzepte: Einstufung und Bewertung(1990) Ludewig, JochenDie "4th Generation Languages" entsprechen dem Katalog einer Fertighausfabrik. Lösungen können aus vorhandenen Komponenten schnell und billig zusammengesetzt werden - oder sie sind nicht möglich. Die Stärken liegen also in Geschwindigkeit und Kosten von Standardlösungen, die Schwächen in der mangelnden Flexibilität bei speziellen Problemen, insbesondere auch bei der Erweiterung vorhandener Software-Systeme.Item Open Access Towards building knowledge on causes of critical requirements engineering problems(2015) Kalinowski, Marcos; Spínola, Rodrigo Oliveira; Conte, Tayana; Prikladnicki, Rafael; Méndez Fernández, Daniel; Wagner, Stefan[Context] Many software projects fail due to problems in requirements engineering (RE). [Objective] The goal of this paper is to gather information on relevant RE problems and to represent knowledge on their most common causes. [Method] We replicated a global family of RE surveys in the Brazil and used the data to identify critical RE problems and to build probabilistic cause-effect diagrams to represent knowledge on their common causes. [Results] The survey was answered by 74 different organizations, including small, medium and very large sized companies, conducting both, plan-driven and agile development. The most critical RE problems, according to those organizations, are related to communication and to incomplete or underspecified requirements. We provide the full probabilistic cause-effect diagrams with knowledge on common causes of the most critical identified RE problems online. [Conclusion] We believe that the knowledge presented in the diagrams can be helpful to support organizations in conducting causal analysis sessions by providing an initial understanding on what usually causes critical RE problems.