including the functional deterioration, the failure possibility, as
well as the device availability. The historical information
contains the previous records about failure data and
development trends, the experience about maintenance
methods and service results.
5) Failure prediction module
Failure prediction is one of the significant features of PHM.
Through comprehensive utilization of the monitoring
parameters, it forecasts development tendency of the
equipment as well as the health status in the future, makes the
appropriate judgments and proposes suggestion or decision
about the equipment maintenance [8-9].
6) Comprehensive coverage module
Comprehensive coverage or health management is another
important feature of PHM and the kernel module of the
maintenance optimization system. It analyzes the current ship
maintenance program and the results of the failure prediction,
proposes a series of support decisions and maintenance
strategies, optimizes the outdated maintenance program.
Afterwards, it sends repair plan to the corresponding ship
through the ship-to-shore radio subsystem, arranges the specific
maintenance task and conducts the maintenance job timely
before the failure of the monitoring system [10-11, 16-17].