Requirements document relations: A reuse perspective on traceability through standards

Our publication in the Software and Systems Modeling Journal 2022 started by observing that relations of views, like requirements documents, are scarcely considered in requirements traceability, despite being a key factor in requirements reuse. Explicit formalized document relations can facilitate review activities to improve consistency and completeness. This is relevant for projects, e.g., in the aerospace sector, with challenges related to complex document dependencies: 1. Several contractors contribute. 2. Requirements from standards are applied in several projects. 3. Reuse of requirements from previous phases. We exploit the concept of "layered traceability", explicitly considering documents as views on sets of requirements with relations between these different representations. Different types of relations and their dependencies are investigated with a special focus on requirement reuse through standards and findings formalized in an Object-Role Modelling (ORM) conceptual model. Automated analyses of requirement graphs based on this model are able to reveal inconsistencies in document integration. We show such queries in Neo4J/Cypher for the EagleEye case study. This work is a step toward better support to handle highly complex requirement document dependencies in large projects with a special focus on requirements reuse and to enable automated quality checks on dependent documents to facilitate requirements reviews.