Research in the Software Engineering Group

My talk in the research group of Prof. Walid Maalej at the University of Hamburg. I gave an overview of the research of my group with details on two recent results: naming the pain in requirements engineering and the relationship between type-3 clones and faults.

Transcript

1. Hamburg, 2016-02-12 Stefan Wagner Research in the Software Engineering Group
2. You can copy, share and change, film and photograph, blog, live-blog and tweet this presentation given that you attribute it to its author and respect the rights and licences of its parts. based on slides by @SMEasterbrook und @ethanwhite
3. Tools Requirements Engineering Safety & Security Engineering Quality Engineering Software Engineering Continuous, Agile & Lean Engineering
4. Requirements Engineering
5. There are mostly isolated investigations of methods in requirements engineering research.
6. Research is not driven by problems from industry.
7. NaPiRE: Naming the Pain in Requirements Engineering Research questions and methods 1. What is the status quo in RE? 2. What is the status quo in RE process standards? 3. What is the status quo in RE improvement? 4. What contemporary problems exist in RE and how do they manifest themselves? 5. Are there observable patterns of expectations, status quo, and problems in RE? Bi-yearly World-wide
8. Countries that conducted surveys in 2014/15 D. Méndez Fernández, S. Wagner, M. Kalinowski, M. Felderer, P. Mafra, A. Vetrò et al. Naming the pain in requirements engineering: Contemporary Problems, Causes, and Effects in Practice. Submited to Empirical Software Engineering.
9. Formal/semi-formal goal models are rarely used in practice. Central Europe North/Eastern Europe North America South America 5 % 18 % 1 % 2 % 5 % 4 % 7 % 7 % Semi-formal Formal
10. Causes for incomplete/hidden requirements
11. Effects of incomplete/hidden requirements
12. Quality Engineering
13. Technische Universität München
14. Class A Class B
15. Class A Class B
16. Class A Class B
18. Often 20%–30% redundancy
19. Inconsistencies Can you spot the difference?
20. How problematic are these inconsistencies? Indicating harmfulness [Lague97]: inconsistent evolution of clones in industrial telecom. SW. [Monden02]: higher revision number for files with clones in legacy SW. [Kim05]: substantial amount of coupled changes to code clones. [Li06], [SuChiu07] and [Aversano07], [Bakota07]: discovery of bugs through search for inconsistent clones or clone evolution analysis. Doubting harmfulness [Krinke07]: inconsistent clones hardly ever become consistent later. [Geiger06]: Failure to statistically verify impact of clones on change couplings [Lozano08]: Failure to statistically verify impact of clones on changeability. [Göde11]: Most changes intentionally inconsistent [Rahman12]: no statistically significant impacts on faults
21. Industrial case study • Investigating evolution of type-3 clones • Relationship with documented faults from issue tracker • Industrial systems Accepted at SANER 2016
22. Research questions RQ1: Do software systems contain type-3 clones? |CT3| / |C| RQ2: Do type-3 clones contain documented faults? |CT3 F| / |CT3| RQ3: Are developers aware of type-3 clones? |IMS| / |IM|, interviews with key developers Clone Groups C (exact and incons.) Inconsistent clone groups CT3 Faulty clone Groups CT3 F
23. Data collection and analysis pport ditor HTML Dash- board v1 v2 v3 Extract Analyse Query for relationships and evolution Extract
24. Study objects System Size (KLOC) Age (Years) Developers A 253 4 10 B 332 5 5 C 454 4 10 Java Automotive domain
25. Quantitative results System A B C Overall Share of type-3 clones 0.56 0.23 0.79 0.52 Share of faulty clone type-3 classes 0.33 0.05 0.03 0.17 Share of simultaneously modified type-3 clones 0.58 0.89 0.92 0.85
26. Qualitative results System A B C General clone awareness x No general clone awareness x x No specific clone awareness x x No clone check while bug fixing x x Clone warning while developing x Common code ownership x Discussion about co-changes x
27. Conclusions • About half of all clone classes are type-3 clones. • Rate of faulty type-3 clones is about 17 %. • There is a difference in awareness of clones and inconsistencies. • This awareness seems to impact how many faults are related to type-3 clones. • Further studies should take this into account. • Making developers aware of clones seems still to be worthwhile.
28. Safety & Security Engineering
29. Verification of safety requirements based on system-theoretic analysis Abdulkhaleq, Wagner, Leveson. A Comprehensive Safety Engineering Approach for Software-Intensive Systems Based on STPA. Procedia Engineering 128:2–11, 2015
30. Continuous, Agile & Lean Engineering
31. Analyse the Scrum process to explore its industrial usage with respect to its variations from the perspective of practitioners.
32. Some results • Some companies work with variations in the process just because they carry legacies from their old, non-agile process. • Allowing short discussions during the Daily Scrum was considered efficient by several companies. • The proposed sprint length is adhered to by most of the companies.
33. Tools Requirements Engineering Safety & Security Engineering Quality Engineering Software Engineering Continuous, Agile & Lean Engineering
34. e-mail phone +49 (0) 711 685- Twitter prof_wagnerst http://orcid.org/0000-0002-5256-8429 University of Stuttgart www.iste.uni-stuttgart.de/se/ Prof. Dr. Stefan Wagner 88455 Institute of Software Technology stefan.wagner@informatik.uni-stuttgart.de Slides are available at www.stefan-wagner.biz.
35. Pictures used in this slide deck Jan and Ivan by Stefan Wagner Clones by Nick Royer (https://flic.kr/p/d1DFPL) bad smell by Jeremy Tarling (https://flic.kr/p/gtS8xX)