Interaction-Based Creation and Maintenance of Continuously Usable Trace Links

Traceability is a major concern for all software engineering artefacts. The core of traceability are trace links between the artefacts. Out of the links between all kinds of artefacts, trace links between requirements and source code are fundamental, since they enable the connection between the user point of view of a requirement and its actual implementation. Trace links are important for many software engineering tasks such as maintenance, program comprehension, verification, etc. Furthermore, the direct availability of trace links during a project improves the performance of developers. The manual creation of trace links is too time-consuming to be practical. Thus, traceability research has a strong focus on automatic trace link creation. The most common automatic trace link creation methods use information retrieval techniques to measure the textual similarity between artefacts. The results of the textual similarity measurement is then used to judge the creation of links between artefacts. The application of such information retrieval techniques results in a lot of wrong link candidates and requires further expert knowledge to make the automatically created links usable, insomuch as it is necessary to manually vet the link candidates. This fact prevents the usage of information retrieval techniques to create trace links continuously and directly provide them to developers during a project. Thus, this thesis addresses the problem of continuously providing trace links of a good quality to developers during a project and to maintain these links along with changing artefacts. To achieve this, a novel automatic trace link creation approach called Interaction Log Recording-based Trace Link Creation (ILog) has been designed and evaluated. ILog utilizes the interactions of developers with source code while implementing requirements. In addition, ILog uses the common development convention to provide issues' identifiers in a commit message, to assign recorded interactions to requirements. Thus ILog avoids additional manual efforts from the developers for link creation. ILog has been implemented in a set of tools. The tools enable the recording of interactions in different integrated development environments and the subsequent creation of trace links. Trace link are created between source code files which have been touched by interactions and the current requirement which is being worked on. The trace links which are initially created in this way are further improved by utilizing interaction data such as interaction duration, frequency, type, etc. and source code structure, i.e. source code references between source code files involved in trace links. ILog's link improvement removes potentially wrong links and subsequently adds further correct links. ILog was evaluated in three empirical studies using gold standards created by experts. One of the studies used data from an open source project. In the two other studies, student projects involving a real world customer were used. The results of the studies showed that ILog can create trace links with perfect precision and good recall, which enables the direct usage of the links. The studies also showed that the ILog approach has better precision and recall than other automatic trace link creation approaches, such as information retrieval. To identify trace link maintenance capabilities suitable for the integration in ILog, a systematic literature review about trace link maintenance was performed. In the systematic literature review the trace link maintenance approaches which were found are discussed on the basis of a standardized trace link maintenance process. Furthermore, the extension of ILog with suitable trace link maintenance capabilities from the approaches found is illustrated.