568-569 / 975
Copyright © 2002 - 2014 Risknowlogy®. All rights reserved. v4
®
‣
1oo1
!
!
!
!
≈
!
‣
1oo2
!
!
≈
Another look at the “Simplified” Equations
PFD
avg
=
λ
du
+
λ
dd
(
)
⋅
t
CE
PFD
avg
=
2 1
−
β
D
(
)
λ
dd
+
1
−
β
(
)
λ
du
(
)
2
t
CE
t
GE
+
β
D
λ
dd
MTTR
+
βλ
du
T
1
2
+
MTTR
⎛
⎝⎜
⎞
⎠⎟
16
PFD
avg
= 1/2 T
1
+ MTTR
PFD
avg
= 1/2 T
1
PFD
avg
= 1/2 T
1