Dependability testing of switching systems in the design phase

Fault simulation techniques that complement analysis techniques, such as FMEA and FTA, have been used for evaluation of the reliability and maintainability performance of AXE switching systems in the design phase. One important application is the simulation of single and multiple (simultaneous) hardware fault situations in a test plant. Faults are randomly chosen in accordance with their expected relative occurrence in normal operation. This principle gives unbiased test results, which are used to: verify the compliance of the design to stated design objectives; verify that the dependability models take all significant transitions caused by fault or maintenance activities into account; and predict the reliability performance and maintainability performance of entire switching offices.<>