210 ◾ System Instantaneous Availability
of integral equation still includes the integral terms, the rectangular formula is used
herein. e iteration form of approximate instantaneous availability is
∑∑∑
∑∑∑
=
+
≤
++
>
===
= ===+=
A
hfhAfg jT
hAfg hA fg
T
j
ijilfil
l
i
i
j
i
j
ji lfil
l
i
ji lfil pi Ti
l
T
l
T
iT
j
i
T
1– ,
g1
2
–(–)
1
0
11
2
–(–)
1
–(–) (– )
11
0
11
0
00
0
0
where A
j
is the approximate instantaneous availability in case A(t) for the system
instantaneous availability t
j
= jh:
f
j
= f(t
j
), g
f(j)
= g
f
(t
j
), g
p(j)
= g
p
(t
j
), j = 1, 2, ...
7.7.2 Discrete-Time Model
e system availability model can be obtained from section 4.4 as follows:
∑∑
==
==
() (,
.
00
0
Ak Pk
kj
j
T
j
k
7.7.3 Model Comparison
Although there is not much sense i ...