What have we learned from the challenges of (semi-) automated requirements traceability? A discussion on blockchain applicability

<br>Over the last three decades, researchers have attempted to shed light into the requirements traceability problem by introducing tracing tools, techniques, and methods with the vision of achieving ubiquitous traceability. However, despite the technological advances, requirements traceability remains problematic for researchers and practitioners. In this scenario, we aim to identify and investigate the main challenges in implementing (semi-)automated requirements traceability, as reported by literature. We carried out a systematic literature review based on the guidelines for systematic literature reviews in software engineering, proposed by Kitchenham. We retrieved 4530 studies by searching five major bibliographic databases and selected 70 primary studies. These studies were analyzed and classified according to the challenges they present and/or address. The systematic literature review revealed 21 challenges of (semi-)automated requirements traceability which led to the derivation of a set of requirements. To address these requirements, blockchain technology was proposed as a suitable solution for software and systems traceability across organizational boundaries. Findings reveal that the most frequently presented and/or addressed challenges are technological challenges, in particular low accuracy of traceability recovery methods. Findings also suggest that further research is needed, especially through case studies or surveys, to explore traceability practices in industrial settings. Finally, based on our findings we recommend researchers to leverage the human facet of tracing, distributed traceability and traceability approaches to support agile and DevOps practices.