Quality Checks Logit Human Reliability (LHR): A New Model to Evaluate Human Error Probability (HEP)
Table 2
Generic tasks.
N°
GGT
k (t = 8 h)
λ [1/h]
µ (h)
σ (h)
A1
Carry out simple single manual action with feedback. Skill-based and therefore not necessarily with the procedure.
0.0050
6.266·10−4
1596.00
618
A2
Start or reconfigure a system from the main control room following procedures, with feedback.
0.0010
4.169·10−5
23988.00
6010
A3
Start or reconfigure a system from a local control panel following procedures, with feedback.
0.0030
1.252·10−4
7987.99
2800
A4
Reconfigure a system locally using special equipment, with feedback, e.g., closing stuck open boiler SRV using gagging equipment. Full or partial assembly may be required.
0.0300
1.269·10−3
787.94
413
A5
Judgment needed appropriate procedure to be followed, based on interpretation of alarms/indications, situation covered by training at appropriate intervals.
0.0100
4.188·10−4
2387.98
1004
A6
Completely familiar, well-designed highly practiced routine task performed to highest possible standards by highly motivated, highly trained, and experienced person, very aware of implications of failure with time to correct potential error.
0.0001
4.167·10−6
239988.00
59995
B1
Routine check of plant status.
0.0300
1.269·10−3
787.94
413
B2
Restore a single train of a system to correct operational status after test following procedures.
0.0070
2.927·10−4
3416.56
1316
B3
Set system status as part of routine operations using strict administratively controlled procedures.
0.0007
2.918·10−5
34273.71
8566
B4
Calibrate plant equipment using procedures; e.g., adjust set point.
0.0030
1.252·10−4
7987.99
2800
B5
Carry out analysis.
0.0300
1.269·10−4
787.94
413
C1
Simple response to a key alarm within a range of alarms/indications providing clear indication of situation (simple diagnosis required). Response might be direct execution of simple actions or initiating other actions separately assessed.
0.0004
1.667·10−5
59988.00
14995
C2
Identification of situation requiring interpretation of complex pattern of alarms/indications. (Note that the response component should be evaluated as a separate GTT.)
