Safety testing of safety critical software based on critical mission duration
Shiping Yang, Nan Sang, Guangze Xiong · 2004
To assess the safety of software based safety critical systems, we firstly analyzed the differences between reliability and safety, then, introduced a safety model based on three-state Markov model and some safety-related metrics. For safety critical software it is common to demand that all known faults are removed. Thus an operational test for safety critical software takes the form of a specified number of test cases (or a specified critical mission duration) that must be executed unsafe-failure-free. When the previous test has been early terminated as a result of an unsafe failure, it has been proposed that the further test need to be more stringent (i.e. the number of tests that must be executed unsafe-failure-free should increase). In order to solve the problem, a safety testing method based on critical mission duration and Bayesian testing stopping rules is proposed.