抄録
In recent years, a big risk exists in chemical plants which have upgrade, complication, and aging. And, ensuring safety by a past approach becomes difficult. In this situation, operation based on a quantitative risk analysis has been required as part of the safety lifecycle also in the field of maintenance and the preventive maintenance. In this paper, it meets the functional safety technology of IEC 61508, and relations of the technology and the theory to the maintenance field are analyzed. At the end introduces how to tackle maintenance in future.