Plant maintenanace method and apparatus

An apparatus for maintaining plant equipment comprising:

• an input unit configured to receive data on inspection, diagnosis, repair and operation histories for equipment that constitute a plant;
• an efficiency and operational-function decay-event tree breakdown unit configured to perform efficiency and operational-function decay-event tree breakdown on efficiency and operational-function decay factors to be expected for the equipment, in order to make an efficiency and operational-function decay-event tree;
• an efficiency and operational-function decay parameter assessment unit configured to predict unreliability of at least one starting item in the efficiency and operational-function decay-event tree;
• an efficiency and operational-function decay unreliability calculation unit configured to calculate unreliability of each item in the efficiency and operational-function decay-event tree based on failure unreliability function;
• an efficiency and operational-function decay prediction unit to calculate efficiency and operational-function decay configured to be expected based on prediction by the efficiency and operational-function decay unreliability calculation unit;
• an efficiency and operational-function decay derived monetary loss calculation unit configured to multiply each unreliability and monetary loss due to efficiency and operational-function decay and a cost of recovery from the decay and accumulate results of the multiplication in accordance with the efficiency and operational-function decay-event tree breakdown;
• a preventive-maintenance expense calculation unit configured to calculate preventive maintenance expenses for preventing the efficiency and operational-function decay;
• and
• an operation and maintenance decision-making unit configured to decide maintenance timing and technique through comparison between the recovery cost and the preventive maintenance expenses.

A method of maintaining plant equipment comprising the steps of:

• receiving data on inspection, diagnosis, repair and operation histories for equipment that constitute a plant;
• performing failure-event tree breakdown on failures to be expected for the equipment, thereby obtaining a failure-event tree;
• predicting unreliability of at least one starting item in the failure-event tree;
• calculating unreliability of each item in the failure-event tree based on a failure unreliability function;
• multiplying each unreliability and a cost of recovery from each failure event in the failure-event tree and accumulating results of the multiplication in accordance with the tree breakdown, thus obtaining a recovery cost;
• calculating preventive maintenance expenses for preventing failure events;
• and
• deciding maintenance timing and technique through comparison between the recovery cost and the preventive maintenance expenses.

A method of maintaining plant equipment comprising the steps of:

• receiving data on inspection, diagnosis, repair and operation histories for equipment that constitute a plant;
• performing efficiency and operational-function decay event-tree breakdown on efficiency and operational-function decay factors to be expected for the equipment, thereby obtaining a efficiency and operational-function decay event-tree;
• predicting unreliability of at least one starting item in the efficiency and operational-function decay event-tree;
• calculating unreliability of each item in the efficiency and operational-function decay-event tree based on failure unreliability function;
• calculating efficiency and operational-function decay to be expected from the calculation based on the failure unreliability function;
• multiplying each unreliability and monetary loss due to efficiency and operational-function decay and a cost of recovery from the decay and accumulating results of the multiplication in accordance with the efficiency and operational-function decay-event tree breakdown;
• calculating preventive maintenance expenses for preventing the efficiency and operational-function decay;
• and
• deciding maintenance timing and technique through comparison between the recovery cost and the preventive maintenance expenses.