Analysis of Architecture Pattern Usage in Legacy System Architecture Documentation

Architecture patterns are an important tool in architectural design. However, while many architecture patterns have been identified, there is little in-depth understanding of their actual use in software architectures. For instance, there is no overview of how many patterns are used per system or which patterns are the most common or most important for particular domains. In addition, little is known of how architecture patterns may interact with each other. We studied architecture documentation of 47 systems to learn about their architecture patterns. Most systems had two or more architecture patterns, and certain patterns were prominent in different application domains. We identified several patterns that are commonly used together, and are beginning to learn how such combinations may impact system quality attributes. This information can be used to help designers select architecture patterns, can help people learn both architectures and patterns, and can be useful in architectural reviews.