Fault tolerant system reliability based on imperfect fault coverage

For computer systems required high levels of reliability, imperfect fault coverage will have a major impact on the overall system reliability when compared with the ideal system with perfect coverage, and the correct estimation of coverage is also important. This paper presents a two-stage sampling estimation to obtain coverage parameter based on fault injection technique. Then we demonstrate a combinatorial model to compute the system reliability based on different fault coverage models. Through an example of tri-module system, we explains the application of two-stage sampling and the impact of imperfect fault coverage on system reliability. The results show that different fault coverage models have different impacts on reliability.