Evaluation of Maintenance Processes in Open Source Software Projects Through Defect and Version Management Systems

While Open Source Software (OSS) is becoming more widespread and popular, its maintenance has become an important issue. However, several aspects of Open Source Software maintenance are unclear; for example, maintenance processes are usually described briefly in the project documentation and the descriptions are very informal and inaccurate. Several earlier studies have examined Open Source Software projects (OSSPs) but they have not provided information about maintenance because they have concentrated on several other aspects such as development and community models. Therefore, in this thesis we study the maintenance of Open Source Software. First, we present an evaluation framework for Open Source Software that can be used to create a general overview of the software, project and related services. From the viewpoint of the software, we cover attributes such as the type of software and intended audience. From the project viewpoint, we cover aspects of the development model and management systems. Since most OSSPs do not provide services to users, it is reasonable to cover external service providers. Second, we present an Open Source Software maintenance process framework. It was developed by studying maintenance activities and the project documents in OSSPs and using ISO/IEC and IEEE standards for software maintenance as a guideline. As a result of this, we noticed that from the theoretical viewpoint the maintenance processes in OSSPs are quite similar to those in the standards. However, maintenance activities may not be performed as described in the project documents. Therefore, we decided to identify attributes and metrics that could be used to measure maintenance processes in the real world. Third, we present an evaluation framework for Open Source Software maintenance that can be used to study OSS maintenance processes through defect reports and software change histories by using defect management systems (DMS) and version management systems (VMS) as data sources. While those systems provide more than enough data about maintenance processes, data retrieval can become a problem. One OSSP can have over 35000 defect reports and 7000 changes in the source code, so manual retrieval and evaluation of the data is not a realistic option. Therefore, we developed an automatic tool, Remote analysis System for Open Source Software (RaSOSS), for data retrieval and analysis. The main contributions of this thesis are these three frameworks and RaSOSS. Universal Decimal Classification: 004.413, 004.415.5 Inspec Thesaurus: computer software; public domain software; software maintenance; software management; project management; system documentation; software standards; error analysis; error handling; data analysis