A Study on the Software Architecture Documentation Practices and Maturity in Open-Source Software Development

The best practices in the industry for Software Architecture (SA) documentation are not always followed, despite it being known that SA documentation can positively influence different aspects of software development. Open-Source Software (OSS) projects often operate in a different manner compared to proprietary software projects. This study investigates contemporary SA documentation practices in OSS projects to gain insights into: (1) what architectural elements are described, (2) what the different description formats and types are, and (3) what the maturity of the architecture description is. The SA description documentation of six OSS projects is identified, classified, and evaluated: VLC, OpenEHR, openKM, GIMP, Audacity, and Home Assistant. The results show that natural language is widely used in describing the architecture, sometimes accompanied by diagrams of informal models. The majority of documentation was found on websites and wikis. The maturity was evaluated by applying the Architectural Capability Model (ArchCaMo). Out of the five maturity levels, most projects did not get past the first level. Only one project reached the second level, and one project showed potential for level three as it was the only project with explicitly documented SA design decisions.