Designing Fault Injection Experiments Using State-Based Model to Test a Space Software

Software for space applications requires significant testing. This paper presents an evaluation of the CoFI testing methodology as applied to actual space software, where deterministic fault cases derived from state-based models were executed using the software-implemented fault injection technique. Different models were used to represent the behavior of embedded software in a real satellite computer under the presence of both normal inputs and external faults in communication, processor, and memory. CoFI methodology was used for model construction, the Condado tool for test derivation, and the QSEE-TAS tool for test execution. In total, 8,620% of 471 fault cases detected errors in the software; this is a very large number, and more so considering that the software had already been tested by the company which developed it before being subject the CoFI methodology.