Focus Group on Architectural Patterns in Practice

Hosted at the Tenth European Conference on Pattern Languages of Programs (EuroPLoP 2005)
06th-10th July 2005
Irsee, Germany

http://www.ipsi.fraunhofer.de/~avgeriou/APP2005

Architectural patterns were one of the very few points, where consensus was achieved in the field of software architecture: their significance is well-established and they are essential to architectural description. Architectural patterns are widely accepted as recurring solutions that solve problems at the architectural design level, and provide a common vocabulary in order to facilitate communication. Architectural patterns also provide the means to reason for the quality attributes of a software system and help to document the design decisions taken by the architect. Regrettably, describing, finding, and applying architectural patterns in practice still remains largely ad-hoc and idiosyncratic. In particular there are certain issues that are problematic:

• A big part of the literature treats architectural patterns (also known as architectural styles) as design templates without having a context, a specific problem to solve or even a rationale. They may not even be considered generic and “timeless” in the Alexandrian sense, but become much more concrete and focused. Is there an essential difference between architectural patterns and styles or is it just a matter of describing the same concept differently?
• What is the granularity of architectural patterns? Can some GOF patterns be considered architectural?
• How are the patterns from all the different catalogues related and how can they be combined (e.g. POSA patterns and SEI architectural styles)?
• How can we apply architectural patterns when designing the architecture of a system? Is there an appropriate modeling language for this purpose? Can we identify common abstractions that can act as primitives for modeling architectural patterns?
• Are the claims of using inter-related sets of patterns in the form of pattern languages or systems of patterns valid in practice?
• How are views related to architectural patterns? Can there be a one-to-one mapping? Or is it rather an N-to-M mapping?
• Which engineering techniques or software development processes/methodologies can integrate the activities of finding, selecting, and applying architectural patterns? How can the design decision based on applying patterns be explicitly documented?

Goals

The goal of this focus group is to examine how practitioners, researchers, developers, etc. make use of the rich but heterogeneous and diverse collection of patterns in the literature. The participants will be asked to reflect and discuss on some of the aforementioned issues that they have come across in practice. They will particularly be asked to share their experiences of applying patterns in practice, in contrast to the theoretical viewpoint of academia. The focus group is intended to initiate what is expected to be a long discussion among interested researchers and practitioners in putting architectural patterns to work.

Format

This short focus group will have the following format:

1. Short introduction to the topic by organizers, handing out a list of architectural patterns for further discussion
2. Summary of position statements by the participants
3. Formation of break-out groups where the above issues are addressed by “war stories”
4. Join and collection of results

Participation

To participate, please send a short position statement by e-mail to paris.avgeriou@ipsi.fraunhofer.de until June 15, 2005. The position statement should very briefly summarize the experience of the participant in applying architectural patterns in practice and/or where the participant stands on any of the aforementioned issues.

Focus Group Organizers

Uwe Zdun
Department of Information Systems, Vienna University of Economics, Austria
zdun@acm.org
http://wi.wu-wien.ac.at/~uzdun/