Prioritize the maintenance of assets.

Asset criticality=SUM（Failure probabilityXFailure result or severityXFailure weight)

For example：

Asset criticality=Failure resulted RBC probability(0-1)XFailure resulted RBC cost(0-10)*20%+Failure resulted production loss cost probability(0-1)XFailure resulted production cost(0-10)*30%+Failure resulted Hygiene & Safety probability(0-1)XFailure resulted HS loss cost(0-10)*20%+Failure resulted Enviromental loss probability(0-1)XEnviromental effect(0-10)*20%+Failure resulted Law broken probability(0-1)XEffect(0-10)*10%。

The criticality of asset decides the criticality of MRO which decides the criticality of spare parts. But also the criticality of MRO is decided by the lead time and annual consumption of spare parts etc.

Risk or probability appraisal formular:：P*S*η/D。P stands for failure probability which value is 0-1；S stands for severity with the value is 0-10，η stands for correcting factor，to assure the value of S is 0-10。D is the detective level。

P value，record as 1 if happend veery day；then the probability will be 0.1 if frequency is once per 10 day. If frequency is 1/100, the the value will be 0.01. Generally, CIL is carried out every 500 running hrs，TBM is based on 1000 running hrs.