In order to provide an operation and maintenance planning aiding system
for a power generation installation which prepares an operation plan for
a plurality of power generation units by making use of actual plant data
and based on a total judgement including a variety of circumstances of
the machine and apparatus or the parts thereof in the power generation
units, in the system the plurality of power generation units 41, 42, 51
and 52, a power supply command center 3 and a service center 1 are
arranged and connected via a communication network 6, the service center
1 obtains the plant data via the communication network 6 from the
plurality of power generation units 41, 42, 51 and 52, calculates in real
time a power generation efficiency of a concerned power generation unit
for every plurality of power generation units 41, 42 51 and 52 by making
use of the obtained plant data and design data of the concerned power
generation unit and prepares an operation and maintenance plan for each
of the power generation units based on the calculated power generation
efficiency.