Toward Architecture Evaluation through Ontology-Based Requirements-Level Scenarios

We describe an approach for evaluating whether a candidate architecture dependably satisfies stakeholder requirements expressed in requirements-level scenarios. We map scenarios to architectural elements through an ontology of requirements-level event classes and domain entities. The scenarios express both functional requirements and quality attributes of the system; for quality attributes, the scenarios either operationalize the quality or show how the quality can be verified. Our approach provides a connection between requirements a stakeholder can understand directly, and architectures developed to satisfy those requirements. The requirements-level ontology simplifies the mapping, acts as the focus for maintaining the mapping as both scenarios and architecture evolve, and provides a foundation for evaluating scenarios and architecture individually and jointly. In this paper, we focus on the mapping through event classes and demonstrate our approach with two examples.