Testing of Safety Systems: Bad Effects and Their Modelling with Comparative Studies
Master thesis
Permanent lenke
http://hdl.handle.net/11250/2568727Utgivelsesdato
2018Metadata
Vis full innførselSamlinger
Sammendrag
Safety systems are used in the process industry for many years. The application of thesesystem is based on IEC 61508 standard. In this standard, proof testing is recommendedin order to achieve the required SIL. It is common to assume that all the proof tests arecomplete and all the failure modes are covered. However, it is not always true.The main objetive of this thesis is to assess the impact of degradation due to proof testand also evaluate the impact of incomplete testing. In order to do that the ATSV andMTSV failure rate models are proposed based on DNV-GL papers. Another approach usingmulti state models are used. The Multiphase Markov model is used to reflect the effectdegradation due to proof testing and test incompleteness.The BOP and the HIPPS valves were used as example to PFD assessment since thereare historical data that theses system can face degradation if a complete test is performed.ii