Non-software examples of software design patterns

Abstract

Many people are overwhelmed by their initial exposure to design patterns. Requests for more examples are common feedback from Design Pattern training courses. Unfortunately, meaningful examples are not always readily avai.Iable. The patterns presented by Gamma, Helm, Johnson, and Vlissides (Gang Of Four) [l] are, by their own admission, elegant solutions to problems rather than de designs that people initially develop. The proprietary nature of software further limits the access to meaningful examples. Although access to examples of patterns may be limited, examples can be found elsewhere. Software Design Patterns have roots in both the work of architect Christopher Alexander, and in the Object movement. According to Alexander, patterns repeat themselves, since they are a generic solution to a given set of forces. The object movement looks to the real world for insights into modeling software relationships. With these dual roots, it is a reasonable hypothesis that the software design patterns should be repeated in real world objects. This workshop presented an opportunity to develop real world examples of the Gang Of Four patterns and explore the insights gained from de process of developing the examples. Participants submitted two or more examples of non-software instances of the Gang Of Four software design patterns. Each participant read all submissions before the workshop. The time was spent examining each example, both to determine its appropriateness and to share suggestions for improvement. The process of determining how well an example fits a particular pattern provided new insight on each of the patterns.