Markov Analysis on Optimal Proof-Testing Interval for Safety-Related Systems  
Author Shinji Inoue


Co-Author(s) Takaji Fujiwara; Shigeru Yamada


Abstract Proof-testing is known as scheduled inspections or maintenance activities to ensure that safety-related systems are working as intended. Generally, the main purpose of the proof-testing is to detect dangerous undetected fault, which cannot be detected by frequently conducted diagnostic testing. Therefore, the prooftesting is important maintenance activities as well as the diagnostic testing. However, the proof-testing is often complicated and is also time-consuming activities. Accordingly, large amount of cost is needed to conduct proof-testing. We discuss analytical methodologies for obtaining optimal proof-testing interval with harmful risk and proof-testing cost by describing the behavior of the safety-related system based on a continuous-time Markov chain. Further, an analytical optimal policy for obtaining economic proof-testing interval is proposed in this paper.


Keywords Functional safety, E/E/PE safety-related systems, Proof testing, DU fault, Optimal proof-testing interval, Continuous-time Markov chain
    Article #:  RQD28-195

Proceedings of 28th ISSAT International Conference on Reliability & Quality in Design
August 3-5, 2023