05 Fakultät Informatik, Elektrotechnik und Informationstechnik

Permanent URI for this collectionhttps://elib.uni-stuttgart.de/handle/11682/6

Browse

Publication Type: search.filters.UBSTyp.KonferenzbeitragStart date: 2017Institute: search.filters.UBSInstitut.Institut für SoftwaretechnologieAuthor: search.filters.author.Wagner, Stefan

Search Results

Now showing 1 - 5 of 5
  • Thumbnail Image
    ItemOpen Access
    Mining Java packages for developer profiles : an exploratory study
    (2017) Ramadani, Jasmin; Wagner, Stefan
  • Thumbnail Image
    ItemOpen Access
    Is the stack distance between test case and method correlated with test effectiveness?
    (2019) Niedermayr, Rainer; Wagner, Stefan
    Mutation testing is a means to assess the effectiveness of a test suite and its outcome is considered more meaningful than code coverage metrics. However, despite several optimizations, mutation testing requires a significant computational effort and has not been widely adopted in industry. Therefore, we study in this paper whether test effectiveness can be approximated using a more light-weight approach. We hypothesize that a test case is more likely to detect faults in methods that are close to the test case on the call stack than in methods that the test case accesses indirectly through many other methods. Based on this hypothesis, we propose the minimal stack distance between test case and method as a new test measure, which expresses how close any test case comes to a given method, and study its correlation with test effectiveness. We conducted an empirical study with 21 open-source projects, which comprise in total 1.8 million LOC, and show that a correlation exists between stack distance and test effectiveness. The correlation reaches a strength up to 0.58. We further show that a classifier using the minimal stack distance along with additional easily computable measures can predict the mutation testing result of a method with 92.9% precision and 93.4% recall. Hence, such a classifier can be taken into consideration as a light-weight alternative to mutation testing or as a preceding, less costly step to that.
  • Thumbnail Image
    ItemOpen Access
    Interdisciplinary system courses - teaching agile systems engineering
    (2019) Seitz, Andreas; Avezum, Mariana; Bruegge, Bernd; Wagner, Stefan
    With the advent of technologies like the Internet of Things, Industry 4.0 and Cyber-Physical Systems, many software engineering courses turn into system engineering courses. Recent advances in technologies such as 3D printing and low-cost micro controllers enable to teach agile hard- and software co-design in system engineering courses. In this paper, we describe Interdisciplinary System Courses (ISC) - a teaching approach based on interdisciplinary projects, light-weight agile techniques and solving real problems by integrating industry customers. We describe our experiences from an exploratory case study where we applied ISC in a two-week international summer school with a customer from the aerospace industry. We derive a set of hypotheses on the effects of ISC.
  • Thumbnail Image
    ItemOpen Access
    Exploratory study of the privacy extension for System Theoretic Process Analysis (STPA-Priv) to elicit privacy risks in eHealth
    (2017) Mindermann, Kai; Riedel, Frederik; Abdulkhaleq, Asim; Stach, Christoph; Wagner, Stefan
    Context: System Theoretic Process Analysis for Privacy (STPA-Priv) is a novel privacy risk elicitation method using a top down approach. It has not gotten very much attention but may offer a convenient structured approach and generation of additional artifacts compared to other methods. Aim: The aim of this exploratory study is to find out what benefits the privacy risk elicitation method STPA-Priv has and to explain how the method can be used. Method: Therefore we apply STPA-Priv to a real world health scenario that involves a smart glucose measurement device used by children. Different kinds of data from the smart device including location data should be shared with the parents, physicians, and urban planners. This makes it a sociotechnical system that offers adequate and complex privacy risks to be found. Results: We find out that STPA-Priv is a structured method for privacy analysis and finds complex privacy risks. The method is supported by a tool called XSTAMPP which makes the analysis and its results more profound. Additionally, we learn that an iterative application of the steps might be necessary to find more privacy risks when more information about the system is available later. Conclusions: STPA-Priv helps to identify complex privacy risks that are derived from sociotechnical interactions in a system. It also outputs privacy constraints that are to be enforced by the system to ensure privacy.
  • Thumbnail Image
    ItemOpen Access
    How do coupled file changes influence how developers seek help during maintenance tasks?
    (2017) Ramadani, Jasmin; Wagner, Stefan
    Software repositories contain a lot of information that can be transformed into suggestions other files they need to modify during maintenance tasks (so-called “coupled changes”). Existing studies however ignore developer feedback and their influence on the developer strategy for getting help during maintenance tasks. We used the Grounded Theory approach to investigate screen capture videos from an experiment to find which information sources developers use to find help and what is their relevance. We compared the frequency as well as the sequence patterns of used information sources both for the developers using coupled change suggestions and those not using them. We found a set of information sources where the developers seek for help and identified two categories of relevance. Also, we discovered that for the tasks using coupled change suggestions, the developers used mostly the internal IDE elements as an information source whereby the developers not using coupled change suggestions often used external sources like the documentation or the web. Coupled change suggestions influence the strategy how the developers seek for help by reducing the search for information on external locations which makes the process of solving maintenance tasks more compact.