Ram terms and definitions – Rolls-Royce 1004227 User Manual
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C
RAM TERMS AND DEFINITIONS
Term Definition
Availability (%) (Avail)
100
1
•
+
−
⎟⎟
⎠
⎞
⎜⎜
⎝
⎛
Hours
Period
Unit
Hours
Outage
Scheduled
Hours
Outage
Forced
where Scheduled Outage Hours = Maintenance
Unscheduled Outage Hours + Maintenance
Scheduled Outage Hours
Reliability (%) (Reliab)
100
1
•
⎟⎟
⎠
⎞
⎜⎜
⎝
⎛
−
Hours
Period
Unit
Hours
Outage
Forced
Forced Outage Factor (%) (FOF)
100
•
⎟⎟
⎠
⎞
⎜⎜
⎝
⎛
Hours
Period
Unit
Hours
Outage
Forced
Scheduled Maintenance Factor (%)
100
•
⎟⎟
⎠
⎞
⎜⎜
⎝
⎛
Hours
Period
Unit
Hours
Outage
Schedule
enance
int
Ma
Unscheduled Maintenance Factor (%)
100
•
⎟⎟
⎠
⎞
⎜⎜
⎝
⎛
Hours
Period
Unit
Hours
Outage
Unschedule
enance
int
Ma
Service Factor (%) (SF)
100
•
⎟⎟
⎠
⎞
⎜⎜
⎝
⎛
Hours
Period
Unit
Hours
Service
Starting Reliability (%) (SR)
100
•
⎟⎟
⎠
⎞
⎜⎜
⎝
⎛
Starts
Attempted
of
Number
Starts
Successful
of
Number
Service Hours per Start (SH/Start)
⎟⎟
⎠
⎞
⎜⎜
⎝
⎛
Starts
Successful
Hours
Service
Average Load
⎟⎟
⎠
⎞
⎜⎜
⎝
⎛
Hours
Service
Generated
Hours
Megawatt
Gross
Mean Time Between Failure (MTBF)
⎟⎟
⎠
⎞
⎜⎜
⎝
⎛
Operation
of
State
a
from
Trips
Hours
Service
Mean Time To Repair (MTTR)
⎟⎟
⎠
⎞
⎜⎜
⎝
⎛
Operation
of
State
a
from
Trips
Trips
from
sulting
Re
Hours
Outage
Mission (Running) Reliability
e
-
λt
where
λ = Failure Rate and
t = Mission Time (SH/Start)