Property-Based Fault Injection: A Novel Approach to Model-Based Fault Injection for Safety Critical Systems

Abstract

With the recent popularity of model-based design and verification (MBDE), fault injection testing at the functional model level is gaining significant interest. The reason for this interest is it aids in detecting design errors and incorrect requirements on fault detection and tolerance features, very early in the development lifecycle. This is evidenced by the fact that functional safety standards like IEC 61508 and ISO 26262 identify fault injection testing as a highly recommended technique for SIL-3 and SIL-4. The main challenges to date with model-based fault injection are lack of completeness in the fault injection space, semi-manual integration and insertion of fault injection modules into the models and manual identification of fault activation conditions. The work presented in this paper describes a novel model-based fault injection technique that is property-based and applies formal model checking verification methods at the functional model level of design thereby guaranteeing a near-exhaustive state, input and fault space coverage. This method also introduces the usage of properties and model checking capabilities to automate the identification of fault activation conditions for all the faults within the fault space. We describe the workflow and implementation of the property-based Fault injection using Simulink Design Verifier and its application on the functional model of a representative safety-critical system.