Camilo Fitzgerald PhD Student UCL Computer Science Resolving Conflicts in Requirements Engineering: A PhD Project Camilo Fitzgerald PhD Student UCL Computer Science 8th January, 2008

Overview A Simple Example Scope of the Project Existing Work Problem Exploration Next Steps Summary Remember: Tell them, Tell them, Tell them

A Simple Example Consider a ‘new mobile phone’ project: Requirement A: Phone must provide GPS. Requirement B: Phone must weigh less than 10g. Domain Property: The lightest GPS device weighs 12g. Possible resolutions include: Elimination? Forget about the GPS (Requirement A). Weakening? The phone may weigh 20g (Requirement B). Live with Conflict? A GPS device could be available next week that weighs less. … Can be hard to spot in a large RE document

Scope of the Project In Perspective: Poor requirements management is the #1 reason for IT project failures1. Management of conflicts plays a big part in this. Conflicts between requirements are commonplace: Only a handful of computer aided detection methods exist. Almost no work done on automated resolution methods. Conclusion: We need better conflict detection/resolution methods and tools. Ultimately, we need a ‘complete’ requirements conflict management tool that covers every stage of a projects lifecycle.

Existing Work Key Related Works Explored So Far: Viewpoints Theory2 KAOS - Goal Oriented Requirements Engineering3 XLinkIt - Repair Actions Paper4 WinWin – Non-Functional Requirements negotiation5 Egyed’s work on UML model inconsistencies6 Features of these works: Mention that it is a very new area. Little done in the way of detection and even less in the way of resolution

Existing Work Work I will be looking into next: Goal modeling with i*7. Conflicting merges in configuration management. Models for collaborative elicitation. The economic approach to conflicts. I’m very interested in more suggestions… Mention that it is a very new area. Little done in the way of detection and even less in the way of resolution

Problem Exploration: Case Study OpenOffice Project: A qualitative analysis of requirement conflicts found in OpenOffice.org’s spreadsheet application. Modeling of conflicts, and their resolution strategies. Main points of interest: Resolutions were usually chosen based upon the level of authority of the actor that proposed them. Conflicts were frequently raised more than once, after a resolution had been chosen. Many examples where the resolution chosen was to ‘live with the conflict’. Full analysis available on weblog: http://www.cs.ucl.ac.uk/staff/C.Fitzgerald More details available on the blog http://www.cs.ucl.ac.uk/staff/C.Fitzgerald/

Problem Exploration: Other Studies UCL ‘Research Information Systems’ Project: Project Aim: To keep complete and up-to-date data on all research projects at UCL. Underlying Conflict: Time & effort of academic staff vs. accuracy of records. A Study of Student Projects MSc students formed groups of ‘Developers’ and ‘Clients’ to produce a requirements document collaboratively. A Wiki will be used next year to produce the requirements document. Editing pages collaboratively could be a useful tool for recording and resolving conflicts. More details on weblog: http://www.cs.ucl.ac.uk/staff/C.Fitzgerald More details available on the blog http://www.cs.ucl.ac.uk/staff/C.Fitzgerald/

Problem Exploration: Ideas Possible criteria for choosing alternative resolution strategies: Stakeholder satisfaction. Stakeholder importance. Pick a resolution that increases the probability of subsequent resolutions. Project development stage. Artefacts altered by a resolution. Analyse resolutions in terms of other conflicts that may arise from them: How can we handle dependencies between conflicts? In what order should conflicts be resolved? At what stage of the project should a conflict be resolved? Most of these ideas are not your own!

Next Steps Looking into: Future Plans: Characterisation of real world resolution strategies. Dependencies between conflicts. Future Plans: Continue with the projects and related work. Find methods for computer aided conflict detection and/or resolution. Implement these methods in a simple tool that is of use to the software engineering community. Produce a thesis! Virtually no work done on first two points

Summary Conflicts exist and need to be managed effectively. Lots of interesting work out there, but we are a long off from a complete conflict management solution. I’m looking into characterisations of the way conflicts are detected and resolved. By the end of three years, I aim to have a tool that will be useful to software engineers. For more information: http://www.cs.ucl.ac.uk/staff/C.Fitzgerald/

References 1 Survey of US software project by Standish Group 2 Finkelstein, A. S., I. (1996). "The Viewpoints FAQ: Editorial - Viewpoints in Requirements Engineering." Software Engineering Journal. 3 Lamsweerde, A. v. and R. Darimont (1998 ). "Managing conflicts in goal-driven requirements engineering " IEEE Transactions on Software Engineering. 4 Nentwich, C., W. Emmerich, et al. (2003 ). Consistency Management with Repair Actions. 25th International Conference on Software Engineering 5 Boehm, B., P. Bose, et al. (1995). Requirements Negotiation and Renegotiation Aids: A Theory-W Based Spiral Approach. 17th International Conference on Software Engineering. 6 Egyed, A. (2007). Fixing Inconsistencies in UML Design Models. 29th International Conference on Software Engineering, ICSE. 7 Yu, E. S. K. (1997). Towards Modelling and Reasoning Support for Early-Phase Requirements Engineering. IEEE International Symposium on Requirements Engineering

Contact Information Camilo Fitzgerald University College London Dept. of Computer Science, MPEB London WC1E 6BT Office: 7.08 Tel: +44 (0)20 7679 3699 (Direct Dial) Fax: +44 (0)20 7387 1397 Email: C.Fitzgerald (at) cs.ucl.ac.uk Web: http://www.cs.ucl.ac.uk/staff/C.Fitzgerald/ Supervisors: Emmanuel Letier & Anthony Finkelstein Introduce yourself, where you come from, what you are doing and how far into the project you are. Tell them what this presentation is.