Test coverage of the safety instrumented system
Diagnostic test and proof test all can detect the dangerous failure of the safety instrumented system. The coverage of the two kinds of test is the main parameter for the assessment of safety instrumented system performance. The diagnostic coverage of independed failure and depended failure are been differentiated by studying the efficiency of the comparison diagnostic test. Then, the more reasonable model for PFD avg of the 1oo2D configuration is builded. The assumption that the proof test coverage is perfect is unreasonable. In fact, the proof test is imperfect. The probability of failure for a safety function is optimized by introducing the proof test coverage.
In this paper,statistical simulation is used to compare the power of six different goodness-of-fit tests for normality.In the simulation,four different skewed normal distributions are used for sampling,and it finally gets the overall ranks of the six tests in terms of power performance.