Context: ISO 26262 requires compilation of traceable work products across the application lifecycle as product based safety evidence. The compilation of such safety evidence is a time consuming and arduous task. Open Services Lifecycle Collaboration (OSLC) is an initiative that supports traceability through tool interoperability. The meta modelling of the ISO 26262 work products in the structure of Resource Description Framework (RDF) can be used for achieving interoperability. Thus, OSLC services used on the RDF exchanged between interoperating tools aids in an effective way of compiling the product based safety evidence for ISO 26262 safety case.

Objectives: Representing the compilation of traceable work product types for the software testing and verification in ISO 26262, in form of a RDF-based conceptual meta-model. Testing and extending the concepts by instantiating the meta-model with work products to be represented in RDF for a case of a truck Electronic Control Unit (ECU) system. Lastly, validating the effectiveness of the conceptual meta-model for its compliance to ISO 26262.

Methods: To realise the objectives, a case study was conducted at Scania CV AB, Södertälje, Sweden, a manufacturer of safety critical ECU systems used in heavy automobiles. The case study was conducted in three consecutive cycles. The first cycle of qualitative inductive content analysis of the ISO 26262 standard and its related document at the company for defining the conceptual meta model. The second cycle of qualitative deductive content analysis for testing, extending and refining the conceptual meta model. The last cycle of validating the effectiveness of the tested and extended conceptual meta model for compliance to ISO 26262.

Results: The main result was the tested, extended and refined RDF based ISO 26262 conceptual meta model depicting traceable work product types for software testing and verification of a safety critical ECU system. The testing and extending of the conceptual meta model was performed with respect to the Main1 (M1) ECU system at Scania. The RDF was defined for the work products of M1 ECU system. Finally, the conceptual meta model was validated for its effectiveness in realising the criteria of abstraction, confirmability and traceability based on ISO 26262. 

Conclusions: Thus, the RDF-based conceptual meta-model depicting product based safety evidence provides a structure for realising the traceability required for compiling the software testing and verification part of ISO 26262 safety case. The meta model was tested by defining the RDF for the work products of a truck ECU system that would be exchanged for achieving interoperability. Finally, the conceptual meta-model was validated for representing the knowledge required for showing traceable product based safety evidence for ISO 26262 safety case.