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Welcome to my private homepage, which gives you an overview on my work, research and teaching. Since I’ve left University, my homepage there does no longer exist so I replicate most of the information that was found there on this page.

PhD Dissertation

Abstract

Still today, the development of effective and high-quality software tests is an expensive and very labor intensive process. It demands a high amount of problem awareness, domain knowledge and concentration from human software testers. Therefore, any technology that can help reduce the manual effort involved in the software testing process – while ensuring at least the same level of quality – has the potential to significantly reduce software development and maintenance costs. In this dissertation, we present a new idea for achieving this by reusing the knowledge bound up in existing tests

Over the last two decades, software reuse and code recommendation has received a wide variety of a attention in academia and industry, but the research conducted in this area to date has focused on the reuse of application code rather than on the reuse of tests. By switching this focus, this thesis paves the way for the automated extraction of test data and knowledge from previous software projects. In particular, it presents a recommendation approach for software tests that leverages lessons learned from traditional software reuse to make test case reuse suggestions to software engineers while they are working. In contrast to most existing testing-assistance tools, which provide ex-post assistance to test developers in the form of coverage assessments and test quality evaluations, our approach offers an automated, proactive, non-intrusive test recommendation system for efficient software test development.

University of Mannheim, 2014

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Research Interests

During my time as a research & teaching assistant in the group of Prof. Dr. Colin Atkinson, my main research interests were in the areas of

while I conducted also research in the following areas during my diploma thesis and when laying the foundations for my main research work:

Teaching

A short overview over my teaching activity

University of Mannheim

  • FS 2013: Softwaretechnik plus Praktikum (English) — Configuration & Change Management
  • FS 2013: Java Programmierkurs (Deutsch)
  • HS 2012: Advanced Software Engineering (English) — Software Development Processes
  • FS 2012: Java Programmierkurs (Deutsch)
  • FS 2012: Softwaretechnik und Programmierpraktikum (Deutsch)
  • HS 2010: Advanced Software Engineering (English)
  • FS 2010: Softwaretechnik und Programmierpraktikum (Deutsch)
  • FS 2010: Java Programmierkurs (Deutsch)
  • HS 2009: Advanced Software Engineering (English)
  • FS 2009: Softwaretechnik und Programmierpraktikum (Deutsch)
  • FS 2009: Java Programmierkurs (Deutsch)

Hochschule Mannheim

  • SS 2016: Software-Enwicklungsprozesse
  • SS 2015: Software-Enwicklungsprozesse
  • SS 2013: Software-Enwicklungsprozesse
  • SS 2012: Software-Enwicklungsprozesse
  • SS 2011: Software-Enwicklungsprozesse

Duale-Hochschule Baden-Württemberg / Mannheim

  • SS 2011: Software Engineering III
  • WS 2010: Software Engineering III
  • SS 2009: Software Engineering III

Professional Service

I served on the following committees as organizer or reviewer

 

and as reviewer for the

Publications

List of Publications

Reuse-Based Test Recommendation in Software Engineering
Werner Janjic
PhD Thesis, University of Mannheim, Mannheim, June 2014

Reuse-Oriented Code Recommendation Systems
Werner Janjic, Oliver Hummel & Colin Atkinson
Recommendation Systems in Software Engineering, Springer, 2014

Utilizing Software Reuse Experience for Automated Test Recommendation
Werner Janjic and Colin Atkinson
International Workshop on Automation of Software Test (AST 2013) co-located with ICSE 2013, San Francisco, USA, 18.05.2013

An Unabridged Source Code Dataset for Research in Software Reuse
Werner Janjic, Oliver Hummel, Marcus Schumacher and Colin Atkinson
Mining Software Repositories (MSR 2013), San Francisco, 18.05.2013

Test-Driven Reuse: Key to Improving Precision of Search Engines for Software Reuse
Oliver Hummel and Werner Janjic
S. Sim & R. Gallardo (ed.): Finding Code on the Web for Remix and Reuse, Springer Verlag, 2013

Towards Better Comparability of Software Retrieval Approaches through a Standard Collection of Reusable Artifacts
Oliver Hummel and Werner Janjic
Seventh International Conference on Software Engineering Advances (ICSEA) 2012., Lisbon, Portugal, 11.2012

Structuring Software Reusability Metrics for Component-Based Software Development
Danail Hristov, Oliver Hummel, Mahmudul Huq and Werner Janjic
Seventh International Conference on Software Engineering Advances (ICSEA) 2012., Lisbon, Portugal, 11.2012

Leveraging Software Search and Reuse with Automated Software Adaptation
Werner Janjic and Colin Atkinson
Intl. Workshop on Search-driven development: Users, Infrastructure, Tools and Evaluation SUITE 2012, Co-located with ICSE, Zürich, Switzerland, 2012, Zürich, 05.06.2012

Der Herr der Codes
Werner Janjic, Marcus Schumacher
Eclipse Magazin, 2.12, S&S Media GmbH, Frankfurt am Main, 27.01.2012

Probieren geht über Studieren — Testgeriebene Wiederverwendung von Software-Komponenten
Oliver Hummel und Werner Janjic
OBJEKTspektrum, 5 / 11, SIGS DATACOM, 26.08.2011

Discrepancy Discovery in Search-Enhanced Testing
Werner Janjic, Florian Barth, Oliver Hummel and Colin Atkinson
SUITE 2011 Co-located with ICSE 2011, Waikiki, Honolulu, Hawaii, USA, 28.05.2011

Search-Enhanced Testing (NIER Track) [AR 23%]
Colin Atkinson, Oliver Hummel, Werner Janjic
ICSE — Intl. Conference on Software Engineering, Waikiki, Honolulu, Hawaii, USA, 26.05.2011

Proposing Software Design Recommendations Based on Component Interface Intersecting
Oliver Hummel, Werner Janjic and Colin Atkinson
Workshop on Recommendation Systems for Software Engineering RSSE 2010, Co-located with ICSE, Cape Town, South Africa, 2010

More Archetypal Usage Scenarios for Software Search Engines
Werner Janjic, Oliver Hummel and Colin Atkinson
Intl. Workshop on Search-Driven Development SUITE 2010, Co-located with ICSE, Cape Town, South Africa, 2010

Lowering the Barrrier to Reuse through Test-Driven Search
Werner Janjic, Dietmar Stoll, Philipp Bostan, Colin Atkinson
Intl. Workshop on Search-Driven Development SUITE 2009, Co-located with ICSE 2009, Vancouver, Canada, 2009

Accelerating Agile Development through Software Reuse
Werner Janjic, Oliver Hummel and Colin Atkinson
Vol. 2, Iss. 1, Agile Journal, 2009

Code Conjurer – Pulling Reusable Software out of Thin Air
Oliver Hummel, Werner Janjic and Colin Atkinson
IEEE Software, August/September, IEEE Computer Society, 08.2008

Evaluating the Efficiency of Retrieval Methods for Component Repositories
Oliver Hummel, Werner Janjic and Colin Atkinson
Proceedings of the International Conference on Software Engineering and Knowledge Engineering (SEKE2007), 2007

Realising High-Precision Component Recommendations for Software-Development Environments
W. Janjic
Dipl.-Inf. Oliver Hummel, Prof. Dr. Colin Atkinson, Mathematik und Informatik, 2007

Supervised Thesis

  • Alexander Angele: “Development and application of a knowledge extraction parser for unit tests in Java”, Diplomarbeit (supervised together with Dipl.-Wirtsch.-Inf. O. Erlenkämper)
  • Oliver Erlenkämper: “Realizing Automated Test-Recommendations in Software Development Environments”, Diplomarbeit, Juni 2013
  • Benjamin John: “Using Algebraic Specifications for Characterizing Tests in Search-Enhanced Testing”, Bachelorarbeit, Juni 2011
  • Martynas Gaurilcikas: “Multi-Version Testing Software — Multiplexer”, Studienarbeit, April 2011
  • Johannes Heurich: “Test-Case Discovery — An Approach for Test-Case Based Knowledge Reuse”, Bachelorarbeit, August 2010
  • Jurek Herwig: “Realizing Discrepancy Driven Testing with an Integrated Development Environment”, Bachelorarbeit, Juni 2010
  • Dominic Hiller: “Test Case Related Dead-Code Discovery in Components Harvested from the Internet “, Bachelorarbeit, Juni 2010
  • Daniel Schönberger: “Feature-Extraktion in Software-Koponenten durch statische Quellcodeanalyse”, Bachelorarbeit, Januar 2010
  • Nona Shoh: “Realisierung einer PM-Gruppenverwaltung in J2EE mit den Technologien JSF und Hibernate”, Studienarbeit, August 2009
  • Marius Eich: “Black-Box-Komponentenwiederverwendung mit Web Services in Eclipse”, Bachelorarbeit, Mai 2009
  • Valeria Yaneva: “Reuse basierte Anwendungsentwicklung in modernen Software IDEs” (Netbeans), Studienarbeit, Mai 2009
  • Thomas Schulze: “Implementierung eines Quellcode Lizenzprüfers als Eclipse Plug-In”, Studienarbeit, April 2009
  • Artur Zeiler: “Implementierung einer Desktop-Suche für wiederverwendbaren Code”, Bacherlorarbeit, Januar 2009
  • Patricius Komarnicki: “Adapting the Siemens testing suite to Java”, Studienarbeit, Januar 2009
  • Michael Roßnagel: “Eclipse perspectives for Software Reuse”, Studienarbeit, Januar 2009

Traveling

Conferences

  • International Conference on Software Engineering (ICSE) 2013, San Francisco, USA, May 2013
  • Mining Software Repositories (MSR) 2013, San Francisco, USA, May 2013
  • International Conference on Software Engineering Advances (ICSEA) 2012, Lisbon, Portugal, November 2012
  • International Conference on Software Engineering (ICSE) 2012, Zürich, Switzerland, June 2012
  • International Conference on Software Engineering (ICSE) 2011, Honolulu, Hawaii, USA, May 2011
  • International Conference on Software Engineering (ICSE) 2010, Cape Town, South Africa, April/May 2010

Workshops

  • Automation in Software Testing (AST) 2013, San Francisco, USA, May 2013
  • Recommendation Systems for Software Engineering (RSSE) workshop: RSSE state-of-the-art presentations, discussions, and networking, Hamburg, April 2013
  • Commit Workshop Software Engineering, Talk on Automated Software Reuse, Mannheim, June 2012
  • 4th Intl. Workshop on Search-driven development: Users, Infrastructure, Tools and Evaluation, Zürich, Switzerland, June 2012
  • 3rd Intl. Workshop on Search-driven development: Users, Infrastructure, Tools and Evaluation, Honolulu, Hawaii, USA, May 2011
  • 2nd Intl. Workshop on Search-driven development: Users, Infrastructure, Tools and Evaluation, Cape Town, South Africa, April/May 2010
  • Eclipse Demo Camp, Forschungszentrum Informatik Karlsruhe, June 2008

Other

  • Guest Lecture at the University of Irvine, California, USA, May 2011 hosted by Prof. Susan Sim

Leading Quote

“If I have seen a little further it is by standing on the shoulders of Giants.” — Sir Isaac Newton