Linking Medical Device Assurance Cases

Traceability and assurance cases (ACs) are crucial for certification of medical devices built on product line platforms. Prone to inconsistencies in handling product lines, monolithic ACs can complicate traceability of claims, arguments and evidence. We previously introduced the separation of assurance for certain medical devices into two linked ACs: a Technological Assurance Case (TAC), addressing system safety concerns disregarding clinical effects on patients; and a Clinical Assurance Case (CAC), addressing safety of a clinical application. A key observed gap is the absence of traceability that links them to extend their utility. We now propose a traceability metamodel as part of TACTICS (Traceable Assurance Cases for Trustworthy Integrated Compliance and Safety), a model-based methodology to support traceability across multiple assurance cases. We present an overview of this traceability process, conceptually, using a TAC/CAC for a medical system as an example, discussing its benefits, challenges and limitations.