A RAM (Reliability, Availability, Maintainability) analysis was carried out for a system of No. 3 furnaces. The aim of the analysis is, firstly, to estimate the availability value and, secondly, to verify it in relation to the target value set by the customer. In particular, the average availability value required must be greater than 98% for a mission time of 5 years (43,800 hours).
This study is based on a previous SIL (Safety Integrity Level) verification of the same oven system. From this analysis, ‘spurious trip’ rates (or spurious STR failure) were extracted, which are considered a critical failure mode because they directly affect system availability. Subsequently, the ‘mean time to spurious failure’ (MTFFS) data, processed with the exSILentia software, were imported into RAMP 7.0 to perform the RAM analysis.
