Sch 11 para 9 Procedure for assessment of achievement of NRVs and CSTs
(1) The first assessment step must verify whether the observed safety performance is complying with the NRV or not. (2) The observed safety performance must be measured by using the measurement units listed in paragraph 14 and data gathered by the Office of Rail and Road in respect of railway accidents and related consequences, with time series which must include the most recent years of observations as specified in paragraph 6. (3) The observed safety performance must be expressed in terms of— (a) safety performance in the single most recent reported year; and (b) moving weighted average (MWA), as specified in paragraph 13. (4) The values returned must then be compared with the NRV, and if one of these values does not exceed the NRV, the safety performance is to be considered acceptable. If this is not the case, the procedure must continue with the second assessment step.