Internati
o
nal
Journal of Ele
c
trical
and Computer
Engineering
(IJE
CE)
V
o
l.
5, N
o
. 4
,
A
ugu
st
2015
, pp
. 74
2
~
74
9
I
S
SN
: 208
8-8
7
0
8
7
42
Jo
urn
a
l
h
o
me
pa
ge
: h
ttp
://iaesjo
u
r
na
l.com/
o
n
lin
e/ind
e
x.ph
p
/
IJECE
Handling Low and High Demand Mo
d
e
on Safety Instrum
e
nted
Function
To
to
k R.
Biyanto
1*
, Fra
n
ky
K
u
su
ma
2
, Hendra
Co
rdov
a
3
, Yerr
y
Sus
at
i
o
4
, Ri
dh
o
B
a
y
u
aji
5
1,2,3,4
Enginer
i
ng Ph
y
s
ics
Dep
a
rtment
,
FTI, Institu
t
Teknologi
Sepul
uh Nopem
b
er
Su
rabay
a
(ITS), In
donesia
5
Civil
Engin
eeri
ng Departm
e
n
t
,
FTSP,
Institut
T
e
knologi
Sepulu
h
Nopem
b
er
Sur
a
bay
a
(ITS)
, In
donesia
Article Info
A
B
STRAC
T
Article histo
r
y:
Received
J
u
n 12, 2015
Rev
i
sed
Au
g
20
, 20
15
Accepted Aug 26, 2015
In this pap
e
r, d
e
mand rate
and
haza
rdous ev
ent frequ
ency
co
nsiderations
which eff
ect
to t
h
e error on
the S
I
L ca
lcu
l
at
ion will b
e
discused
.
The var
i
ous
value of hazardo
us event frequen
c
y
and demand r
a
te will be ev
alu
a
ted in
this
paper.
The r
e
sult of this p
a
per
is when hazar
dous event freq
u
ency
10E-
06/y
ear
and PFD’s safeguard 0.00002, with
test interv
al 1
y
e
ar
, the SILs of
low and high d
e
mand start showing differ
e
nt SIL at d
e
mand 5.1/year. At th
at
point, eng
i
ne
er shouldn’t use sim
p
lified form
ul
a for low dem
a
nd, because
i
t
will provide diff
erent SIL ta
rget
than sim
p
lified
high dem
a
nd form
ula or the
original
exponential formula. The requi
r
e
d SIL targets are SIL
2 and SIL 1,
for simplified
low demand for
m
ula a
nd simplified h
i
gh d
e
mand formula,
respectively
.
Th
erefore,
it should be ta
ken
more attention and
consideration
for various
valu
e of hazardous
ev
ent
fr
equen
c
y
with var
i
ous demand rate.
Keyword:
SIL d
e
term
in
atio
n
Dem
a
nd rat
e
Hazardous
eve
n
t freque
ncy
Lo
w dem
a
nd
Hi
g
h
dem
a
nd
Copyright ©
201
5 Institut
e
o
f
Ad
vanced
Engin
eer
ing and S
c
i
e
nce.
All rights re
se
rve
d
.
Co
rresp
ond
i
ng
Autho
r
:
Tot
o
k R
.
B
i
y
a
nt
o
In
st
ru
m
e
n
t
atio
n
,
Pro
cess C
ontro
l an
d Op
timizatio
n
En
gi
neeri
n
g
P
h
y
s
i
c
s De
pt
.
In
d
u
st
ri
al
Tec
h
nol
ogy
Facul
t
y
I
T
S Sur
a
b
a
ya 6
011
1, I
ndo
n
e
sia
Em
a
il : trb
@
ep
.its.ac.i
d
1.
INTRODUCTION
Risk
calcu
lation
tak
e
n
as t
h
e co
m
b
in
atio
n
o
f
lik
e
l
i
h
o
od
and
seve
ri
t
y
o
f
l
o
ss e
v
e
n
t
s
.
Ex
po
ne
nt
i
a
l
not
at
i
o
n a
n
d
o
r
de
r
of m
a
gni
t
ude
hel
p
us
gr
asp
vast
ra
n
g
e
s
suc
h
as
t
h
ose
use
d
i
n
ri
s
k
c
a
l
c
ul
at
i
ons
[1
,
2]
. T
h
e
o
r
d
e
r of m
a
g
n
itu
d
e
o
f
a sp
ecific risk cou
l
d
b
e
re
du
ced
u
n
til to
lerab
l
e
lev
e
l b
y
im
p
l
emen
tin
g
SIS (Safety
Inst
rum
e
nt
ed
Sy
st
em
) [3
,4]
.
The
s
p
eci
fi
c
co
nt
r
o
l
f
u
nct
i
ons
pe
rf
o
r
m
e
d
by
S
I
S
are
cal
l
e
d S
I
F
(
S
afet
y
Inst
rum
e
nt
ed F
unct
i
o
n
)
.
SIL targ
et d
e
term
in
atio
n
in
safety in
stru
m
e
n
t
ed
fu
n
c
tion
is v
e
ry im
p
o
r
tan
t
. SILs are th
e
fu
nd
am
en
tal
co
n
c
ep
ts to
main
tain
th
e syste
m
in
safe con
d
ition
.
Th
e
SILs con
s
ist o
f
fou
r
lev
e
ls for
m
a
k
e
clasific
atio
n
of
th
e safety in
teg
r
ity con
d
ition in
th
e safety
fun
c
tion
.
Safety co
st co
n
s
i
s
t o
f
co
st o
f
cap
ital,
m
a
in
ten
a
n
c
e,
o
p
e
ration
and
in
suran
ce are
p
r
op
ortio
n
a
l
with
SIL targ
et
Lev
e
l, h
i
g
h
e
r
SIL targ
et will in
crease th
e co
st and
vice ve
rsa
[1]. SIL
-
target val
u
es a
r
e calcula
ted base
d
on t
h
e
hazardous
e
v
ent
fre
qu
ency
which is
one
of t
h
e
m
o
st
im
port
a
n
t
vari
a
b
l
e
s i
n
SIL
o
f
SIF
det
e
rm
i
n
at
i
on.
Som
e
resear
cher
ha
ve
be
en e
xpl
ore
d
g
e
neri
c
algorithm
s
to
estim
a
te
hazardous
e
v
ent fre
que
ncy base
d
on
vari
ous m
odel of
dem
a
nd
m
ode [4]. T
h
ere are
t
w
o o
p
erat
i
o
n m
odes
of
SI
F base
d
o
n
IEC
61
5
0
8
st
an
da
r
d
, t
hose
are l
o
w
dem
a
nd an
d
hi
g
h
dem
a
nd
m
ode [5]
.
The
ori
g
i
n
al
b
a
si
c equat
i
o
n f
o
r
bot
h m
odes
t
h
at
expl
ai
n t
h
e rel
a
t
i
ons
hi
p
bet
w
ee
n haza
r
d
o
u
s e
v
e
n
t
fre
que
ncy
(H
),
dem
a
nd
ra
te (D
), a
n
d tar
g
et failure
rate
(
λ
) is a
n
e
x
po
ne
ntial fo
rm
ula [6]
.
To
sim
p
lified
th
e calcu
latio
n o
f
d
e
m
a
n
d
rate in
ap
p
licatio
n, th
e en
g
i
n
e
er u
s
e
fo
rm
u
l
a fro
m
IEC
61508.
In IEC
61508, to sim
p
lified
the
equat
i
on
for each de
mand
rate, t
h
e
exponetial form
ula is converted to
aritm
e
tic
formula using Maclaurin
se
ries. Recently, it
has bee
n
found
that sim
p
lified equation for l
o
w
Evaluation Warning : The document was created with Spire.PDF for Python.
I
S
SN
:
2
088
-87
08
I
J
ECE Vo
l. 5
,
N
o
. 4
,
Au
gu
st 2
015
:
74
2
–
74
9
7
43
d
e
m
a
n
d
will produ
ce erro
r in
λ
t
a
r
g
et
i
f
t
h
i
s
eq
uat
i
o
n i
s
a
ppl
i
e
d
i
n
hi
gh
dem
a
nd. M
o
re
ove
r,
i
t
co
ul
d
affect
wro
ng SIL
d
e
term
in
atio
n
[1
]. If
p
r
actitio
n
e
rs u
s
e wro
n
g
ap
pro
ach or equ
a
tio
n to d
e
termin
e SIL, th
e
resu
lt
will h
a
v
e
d
i
fferen
t
SIL v
a
l
u
e
th
at affected
to th
e safety
co
st
. Safety co
st inclu
d
e
o
f
cap
ital co
st, m
a
in
ten
a
n
c
e
co
st,
o
p
eration co
st an
d in
suran
c
e co
st
will in
crease,
if t
h
e SIL v
a
l
u
es are ov
er
estim
a
t
e. Th
is
p
a
p
e
r will
di
scuss
h
o
w t
o
ove
rcom
e t
h
i
s
err
o
r a
nd e
xpl
ore t
h
e
regi
m
e
or l
i
m
i
t
val
u
e of dem
a
nd
rat
e
t
h
at
affect
ed
SIL
v
a
lu
e. Variou
s
v
a
lu
e
of
d
e
m
a
n
d
rate
(D)
will b
e
u
s
ed
in th
i
s
stud
y and
app
lied
in th
e stud
y case.
2.
INTERNATIONAL ELECTROTECHNICAL
COMMISSION (IEC
61
508
)
IEC 615
08
p
r
ov
id
es a m
e
th
od
to
d
e
term
in
e safety requ
iremen
ts to
ach
iev
e
th
e
requ
ired
fun
c
tio
n
a
l
safety on electrical, electro
ni
c an
d
pr
o
g
ram
m
a
bl
e el
ect
ro
ni
c
sy
st
em
s. Thi
s
s
t
anda
rd
di
st
i
n
g
u
i
s
hes
t
h
ree m
o
d
e
s
of o
p
e
r
at
i
on sa
fet
y
funct
i
o
n.
Th
ose are l
o
w
dem
a
nd
m
ode,
hi
gh dem
a
nd
m
ode, and co
n
t
i
nuo
us m
ode. Every
m
odes of
o
p
e
r
at
i
on a
r
e
defi
n
e
d as
f
o
l
l
o
w
s
i
n
Ta
bl
e
1.
Tabl
e 1. IEC
6
1
5
0
8
E
d
2 –
M
ode
s of o
p
erat
i
o
n
M
ode Descr
i
ption
L
o
w De
m
a
nd M
o
d
e
Safety
Function dem
a
nd r
a
te is less th
an or
equal to once a
y
ear
High Dem
a
nd
M
ode
Safety
Function dem
a
nd
rate
is great
e
r
than once a
yea
r
Continu
ous M
ode
Safety
Function is
ope
r
a
ting as a continuous co
ntr
o
l fun
c
tion
Th
e SIF co
u
l
d b
e
ap
p
lied
in d
e
m
a
n
d
m
o
d
e
o
r
con
tin
uous
m
o
d
e
. I
t
is
n
o
t
clear
wh
ich
m
o
d
e
s o
f
ope
rat
i
o
n sh
ou
l
d
be ap
pl
i
e
d t
o
El
ect
ri
c/
El
ect
ro
ni
c/
Pr
ogrammable Electronic Safety-Related Syste
m
s (E/E/PE
SRS(s)),
reelated
to
th
e d
e
m
a
n
d
-state p
r
ob
ab
ility an
d
th
e sp
uriou
s
d
e
m
a
n
d
frequ
en
cy [4]. IEC 6
1
5
0
8
ap
p
lies
diffe
re
nt failur
e
param
e
ters for
defini
n
g
the
safety
in
t
e
gri
t
y
l
e
vel
.
It
depe
ndi
ng
on t
h
e m
ode
of
ope
rat
i
o
n. F
o
r
lo
w
d
e
m
a
n
d
m
o
d
e
, th
e failu
re m
easu
r
e is b
a
sed
on
av
erag
e
p
r
ob
ab
ility o
f
dang
erous failu
re
on
de
m
a
n
d
(
P
FD
avg)
,
wher
eas
f
o
r
h
i
gh d
e
m
a
n
d
m
o
de is b
a
sed on
av
er
ag
e
f
r
e
qu
en
cy of
d
a
n
g
e
ro
u
s
f
a
ilur
e
p
e
r ho
ur
.
Targete
d
failure for eac
h m
o
de are ta
bulated
in Ta
ble 2.
Tabl
e
2. T
a
r
g
et
fai
l
u
re:
l
o
w
de
m
a
nd a
n
d
hi
gh
dem
a
nd m
ode
Safety Integrit
y
Le
vel
(SIL
)
L
o
w De
m
a
nd M
o
d
e
High Dem
a
nd
M
ode
Average
PROBABIL
ITY
of
Danger
ous Failur
e
on
Dem
a
nd (PFDavg)
Average FRE
QUE
NCY
per
hour
of a Danger
ous Failur
e
1
≥
10-
2 to < 10-
1
≥
10-
6 to < 10-
5
2
≥
10-
3 to < 10-
2
≥
10-
7 to < 10-
6
3
≥
10-
4 to < 10-
3
≥
10-
8 to < 10-
7
4
≥
10-
5 to < 10-
4
≥
10-
9 to < 10-
8
2.
1.
SIL
(
S
a
f
et
y In
te
gri
t
y L
e
vel
)
The
IEC
6
1
5
0
8
ass
u
m
e
s t
h
at
ove
r al
l
sy
st
em
com
p
ri
se of
Eq
ui
pm
ent
Un
de
r C
o
nt
r
o
l
(E
UC
) t
h
at
pr
ot
ect
ed
by
E
U
C
c
ont
r
o
l
sy
st
em
(s), a
n
E/
E/
PE SR
S
(
s)
,
anot
her
t
ech
no
l
ogy
base
d SR
S(s)
a
n
d
an
E
x
t
e
r
n
a
l
Risk Reduction Facility (ER
R
F). The
EUC
control system
(s) controls
EUC
to avoid
specific
hazardous e
v
ent
that
m
a
y be happe
ne
d [4]. T
h
e hazardous e
v
ent is well-
de
fined as a
n
e
v
e
n
t that arise conse
que
nce in
harm
,
i.e. in
ju
ry, fatalities, an
d
affect to
th
e p
r
op
erty an
d
/
o
r
env
i
ro
n
m
en
t [7
]. The SRSs an
d
ER
RF are redu
ndan
t
o
f
the sub-system
preventing
hazardous
event when EUC contro
l system
fai
l
s to control EUC under safety
co
nd
itio
n. SIL sh
ou
ld
b
e
d
e
t
e
rm
in
ed
to
answer th
e
qu
estio
n
wh
et
h
e
r instru
m
e
n
t
ed
p
r
o
t
ectio
n
is n
e
ed
ed
t
o
ach
iev
e
t
h
e
requ
ired
lev
e
l
of safety.
IEC
61
5
08
pr
ovi
des va
ri
o
u
s
m
e
t
hods fr
o
m
t
h
at
engi
nee
m
a
y choose
i
t
.
These
m
e
t
h
o
d
s ar
e
st
at
em
ent
s
i
n
t
h
e sect
i
o
n
of
t
h
e st
a
nda
rd
an
d a
r
e
not
o
b
l
i
g
at
ory
.
Le
vel
of
SIL
f
o
r
hi
gh
d
e
m
a
nd i
s
det
e
r
m
i
n
e
d
by
λ
(A
vera
ge
Fre
que
ncy
pe
r
ho
u
r
o
f
a Da
n
g
er
o
u
s Fai
l
u
r
e
), w
h
e
r
eas It
i
s
det
e
rm
i
n
ed by
PFDa
v
g o
f
SI
F fo
r
l
o
w dem
a
nd. T
h
e val
u
e o
f
λ
i
s
cal
cul
a
t
e
d i
n
o
r
de
r t
o
m
a
t
c
hed
wi
t
h
P
F
Da
v
g
o
f
hi
g
h
dem
a
nd a
n
d
l
o
w
dem
a
nd
.
2.
2. Th
e
Ma
th
ematic
a
l F
o
r
m
ula
to
C
a
lcu
l
ate
SIL
The expone
ntial form
is
a basic form
ula to calcu
late SIL fo
r si
n
g
l
e ch
ann
e
l SIF, as sh
own
in
Equ
a
tio
n 1 [6
]:
Evaluation Warning : The document was created with Spire.PDF for Python.
I
J
ECE
I
S
SN
:
208
8-8
7
0
8
H
and
lin
g
Lo
w a
n
d
H
i
gh
D
e
ma
nd
Mod
e
on
Sa
fety
In
strum
e
n
t
ed
Fun
c
tion
(
T
ot
ok
R.
Bi
ya
n
t
o)
74
4
H
=
λ
(1
-
e
xp
(-
DT
/2
))
(1
)
wh
ere::
H
=
Hazardou
s ev
en
t frequ
e
ncy stated
th
e
pro
b
a
b
ility o
f
h
a
zard m
a
y o
ccu
r (year
-1
)
λ
= T
h
e
re
qui
r
e
d
dan
g
e
r
o
u
s
f
a
ilure rate
o
f
a
SIF
(y
ear
-1
)
D
=
Th
e rate at
wh
ich
a pro
t
ectiv
e syste
m
is called
on
to act
(year
-1
)
T
= T
h
e tim
e between
succes
s
i
ve test (year)
The e
q
uat
i
o
n
coul
d
be m
u
l
t
i
pl
y
by
ot
he
rs
PFD
o
f
ER
R
F
, i
f
t
h
ere
i
s
e
x
i
s
t
i
ng
pasi
ve
g
u
ar
d i
n
pl
ant
s
a
fet
y
sy
st
em
. Equat
i
on
(
1
)
co
ul
d
be
rep
r
ese
n
t
as E
quat
i
o
n
(
2
) a
n
d
co
ul
d
be
use
d
t
o
cal
cul
a
t
e
t
h
e
req
u
i
r
e
d
da
ng
ero
u
s
failure rate (
λ
) of
a
SI
F.
λ
1e
x
p
(2
)
The dem
a
nd rate (D) of SIF could
be vary
depe
nd
on est
i
m
a
t
i
on of specif
ic hazardous event that
m
a
y
occur i
n
t
h
e pl
ant
.
T
h
e
dem
a
nd rat
e
coul
d be
very
sm
al
l
or very
l
a
rge. I
f
t
h
e d
e
m
a
nd rat
e
so
sm
al
l
con
s
i
d
ere
d
a
s
l
o
w
dem
a
nd,
he
nce E
q
uat
i
o
n
(
1
)
co
ul
d
be
de
r
i
ved a
s
f
o
l
l
o
ws
:
λ
1
1
2
⋯
λ
or
or
(3
)
In a
not
her
han
d
, i
f
t
h
e d
e
m
a
nd rat
e
o
f
a SIF
i
s
l
a
rge, i
t
i
s
consi
d
ere
d
as hi
gh
dem
a
nd, t
h
eref
ore t
h
e
va
l
u
e of
ex
pon
en
tial form
is n
ear t
o
zero. Th
erefore t
h
e
Equ
a
tio
n (1) will
b
e
represen
t as Equ
a
tion
(4) :
λ
1
0
λ
(4
)
It
sh
o
w
s t
h
at
E
quat
i
o
n
(
4
)
d
o
e
sn’t
c
o
nsi
d
e
r
D.
It
m
a
kes t
h
e req
u
i
r
e
d
da
n
g
er
o
u
s fai
l
ure
rat
e
as a
n
c
ons
t
a
nt
at
any
dem
a
nd ra
t
e
val
u
e. It
pr
o
v
i
d
es
di
ffe
re
nt
resul
t
com
p
are to
th
e orig
inal eq
u
a
tion
in
Equ
a
tio
n
(2).
Fin
a
lly,
the affect
of si
m
p
lified equation provi
des e
r
ror in
SIL d
e
termin
atio
n
for sp
ecific dem
a
nd
rate case.
2.
3.
Form
a
t
i
o
n o
f
E
RRF
ER
R
F
co
ul
d
b
e
arra
n
g
ed
suc
h
as a
pa
ral
l
e
l
or
se
ries st
uctures. T
h
e c
o
nce
p
t for calculating PFDa
vg
of ERRF is ve
ry im
portant,
because it can affect to
the SIL of the sys
t
e
m
. The value of ERRF could be
m
u
lt
i
p
l
y
or ad
ded t
o
Eq
uat
i
o
n (
1
)
de
pen
d
o
n
t
h
e f
o
rm
ati
on use
d
bet
w
ee
n SI
F an
d ER
R
F
. If t
h
e co
n
n
ect
o
n
bet
w
ee
n SIF a
nd ER
R
F
i
s
i
n
seri
es st
ruct
u
r
e, hence “a
dd”
operat
o
r i
s
us
ed, an
d t
h
e “
m
ult
i
p
l
y
” oper
a
t
o
r i
s
u
s
ed
if
th
e conn
ecton
b
e
tw
een
SI
F an
d
ER
RF is in
p
a
rallel stru
cture.
For
exam
ples,
in Figure 1
the
r
e are
two
relief v
a
l
v
es
or two h
i
g
h
lev
e
l
trip
s
syste
m
in
p
a
rallel stru
ct
u
r
e.
Fi
gu
re 1.
Tw
o ER
R
F
i
n
paral
l
el
Let th
e
A
h
a
s
PFDavg
A
and
B h
a
s
PFDavgB, th
en
th
e PFDavg
of th
e syste
m
is
∗
(5
)
Evaluation Warning : The document was created with Spire.PDF for Python.
I
S
SN
:
2
088
-87
08
I
J
ECE Vo
l. 5
,
N
o
. 4
,
Au
gu
st 2
015
:
74
2
–
74
9
7
45
Fi
gu
re
2.
Tw
o
ER
R
F
i
n
se
ri
es
For t
h
e sy
st
em
i
n
seri
es form
at
i
on (Fi
g
u
r
e 2
)
, i
f
t
h
e A has
PFDa
v
gA a
nd
B
has PFDa
v
g
B
, and s
ubse
q
uent
l
y
the PFDa
vg of
the system
is
∗
Or
(IF
PF
Da
vgA
and
PF
DavgB are
sm
all)
(6
)
There
should
be consi
d
ere
d
if the syste
m
/equipm
ents ar
e arra
renge
d
in in series,
the PFD of each c
o
mpone
n
ts
shoul
d
have
s
m
all value or i
n
a
not
her word re
liability of c
o
m
pone
nt s
h
ould be
hi
gh val
u
e.
3.
RESULTS
A
N
D
DI
SC
USI
O
NS
3.
1. SIL
Deter
m
i
n
ati
o
n
i
n
a
Case
S
t
ud
y
The case st
udy
of
pr
ocess
pl
a
n
t
desc
ri
be
d
be
l
o
w i
s
kn
oc
ko
u
t
dr
um
separat
o
r t
h
at
i
t
i
s
t
a
ken f
r
om
[1]
.
The sc
hem
a
t
i
c
or
p
r
oce
ss
fl
o
w
di
ag
ram
i
s
sho
w
s i
n
Fi
g
u
re
3.
Fi
gu
re
3.
Pr
oce
ss fl
o
w
di
a
g
ra
m
of t
h
e sy
st
e
m
under
st
u
d
y
[1
]
Hyd
r
o
c
arbon
gas stream
fro
m
v
a
ri
ou
s section
o
f
t
h
e
u
p
strea
m
p
l
an
t is fl
ows in
t
o
th
e separato
r three
pha
se
an
d
i
t
i
s
separat
e
d
i
n
t
o
wat
e
r, oi
l
an
d gas base
d on
t
h
e phase
o
f
hy
dr
ocar
b
o
n
m
o
lecul
e
. If
t
h
e ga
s
fl
o
w
rate enter i
n
to
the sepa
rator t
h
ree
phase in
exceeds capa
c
ity of se
parat
o
r,
it will lead to th
e haza
rdous eve
n
t
d
u
e
to ov
erpressrue co
nd
itio
n. Rel
easing
o
f
th
e h
y
d
r
o
c
arbon
to th
e en
v
i
ron
m
en
t/air du
e t
o
o
v
erpressure
separat
o
r c
o
ul
d l
ead t
o
an e
xpl
osi
o
n. T
h
e
expl
osi
o
n
c
oul
d ha
rm
peopl
e
,
en
vi
r
onm
ent
,
and ca
use e
q
u
i
pm
ent
dam
a
ge,
he
nce
o
v
er
pre
ssu
re SIF w
oul
d be
i
n
st
al
l
e
d.
The
1o
o
3
vot
i
ng
o
f
t
h
e
sens
ors c
a
n
be c
o
nsi
d
e
r
ed
t
o
ov
ercom
e
t
h
e co
m
m
on cause
f
a
i
l
u
re at
t
h
i
s
stage, he
nce it
is sufficient pa
rt to tr
eat the s
y
ste
m
as a sin
g
le channel sa
fety fu
n
c
tion
.
Plan
t d
e
sign
er sh
ou
l
d
i
n
st
al
l
pasi
ve
pr
ot
ect
i
o
n
s
u
c
h
as
a
b
u
rst
i
n
g
di
sc
an
d
r
upt
ure
pi
n
val
v
e
and
cal
cul
a
t
e
PFDa
v
g
of
ER
R
F
f
r
om
Evaluation Warning : The document was created with Spire.PDF for Python.
I
J
ECE
I
S
SN
:
208
8-8
7
0
8
H
and
lin
g
Lo
w a
n
d
H
i
gh
D
e
ma
nd
Mod
e
on
Sa
fety
In
strum
e
n
t
ed
Fun
c
tion
(
T
ot
ok
R.
Bi
ya
n
t
o)
74
6
PFD
o
f
bu
rstin
g
d
i
sc, ru
p
t
ure p
i
n
v
a
lv
e an
d
p
r
ob
ab
ility o
f
ign
itio
n
.
Th
e ERRF is co
m
p
o
s
ed
as
parallel
d
e
sign
, th
er
efor
e th
e PFD
a
v
g
o
f
(
E
RRF)
=
0
.
0
1*0
.0
1*0
.2
=
0
.
0
000
2.
Dem
a
nd rate t
h
at us
e in t
h
is
researc
h
is
22/year
, a
nd t
h
e
hazardous
eve
n
t freque
ncy is
determ
ined
ab
ou
t 1
E
-06
/
year. Using
h
i
gh
d
e
m
a
n
d
appro
a
ch
in
Eq
u
a
tion
(5), t
h
e
failu
re
rate will b
e
sh
own as
fo
llow:
λ
x 0.01
x
0
.
01 x
0
.
2
= 10-
6 per
year
λ
= 5.
7 x 10
-6
p
e
r ho
ur
R
e
fer t
o
t
h
e Ta
bl
e 2
(hi
g
h de
m
a
nd c
o
l
u
m
n
),
t
h
e
λ
is categorized as
SIL
1. Howe
ver
,
I
f
u
s
i
ng t
h
e l
o
w
de
m
a
nd
ap
pro
ach in
Equ
a
tio
n (4
), the
failu
re
rate
will b
e
sho
w
n
as fo
llo
w:
.
= 0.002
3
R
e
fer t
o
t
h
e T
a
bl
e 2 (l
ow
de
m
a
nd col
u
m
n
), t
h
e
λ
i
s
cat
egori
z
e
d
as SIL
2. It
co
ul
d be
concl
ude
d t
h
at
usi
n
g
hi
g
h
dem
a
nd a
p
p
r
oach
t
h
e
SI
F o
f
t
h
i
s
sy
st
em
i
s
SIL
1 t
h
at
su
ffi
ci
ent
t
o
a
c
hi
eve
safet
y
r
e
qui
rem
e
nt
. H
o
we
ve
r
.
If t
h
e
SIF
use
SIL
2 as a saf
e
t
y
requi
rem
e
nt
due t
o
usi
n
g
l
o
w
dem
a
nd f
o
rm
ul
a, i
t
i
n
creases cost
o
f
c
a
pi
t
a
l
,
ope
rat
i
o
n
a
n
d
m
a
i
n
t
e
nance.
3.
2. T
h
e
Devel
o
pmen
t
of
SI
L
Cal
c
ul
at
or
f
o
r
Vari
ous
De
mand
R
a
te
The case
s
h
o
w
s t
h
at
cal
cul
a
t
i
ons
usi
n
g l
o
w
and
hi
gh
dem
a
nd
f
o
rm
ul
a p
r
o
v
i
d
e
d
i
n
I
E
C
6
1
5
0
8
hav
e
pot
e
n
t
i
a
l
err
o
r
or
wr
o
ng
SIL
t
a
rget
i
n
S
I
F
whe
n
t
h
e
de
m
a
nd rat
e
i
s
h
i
gh.
The
r
ef
ore
,
t
o
hel
p
e
n
gi
n
eer i
n
det
e
rm
i
n
e SIL
t
a
rget
i
n
vari
o
u
s dem
a
nd
, t
h
e
SIL cal
cul
a
t
o
r
i
n
M
a
t
l
a
b en
v
i
ro
nm
ent
was devel
ope
d as s
h
o
w
n
in
Figure
4
.
Th
is calcu
lator
o
u
t
p
u
t
is a
g
r
ap
h th
at it can
esti
m
a
te
λ
whe
n
use hi
g
h
de
m
a
nd
a
p
p
r
oac
h
or
l
o
w
dem
a
nd ap
p
r
oa
ch
wi
t
h
at
di
f
f
e
r
ent
dem
a
nd r
a
t
e
.
Fi
gu
re
4.
The
s
i
m
u
l
a
t
i
on co
de
f
o
r
SIL
cal
cul
a
t
o
r
The input of the calculator
are th
e hazardous eve
n
t freque
ncy (H),
PFD
of
ERRF (PFDavg ERRF),
an
d test in
terval (T).
At th
e en
d of sim
u
lati
o
n
, th
e m
a
xim
u
m
dem
a
nd
rat
e
t
h
at
e
ngi
neer
sh
o
u
l
d
c
o
nsi
d
er
wi
l
l
provide by
the calculator.
Us
i
n
g the case
tha
t
has
descri
bed before, T
h
e
re
sult of calculat
o
r is a
n
plot
be
tween
λ
o
r
P
F
Da
v
g
a
n
d
dem
a
nd
rat
e
as s
h
o
w
n i
n
Fi
gu
re
5
bel
o
w
:
Fi
gu
re
5.
O
u
t
p
ut
o
f
cal
c
u
l
a
t
o
r
as
λ
/
P
F
D
i
n
v
a
ri
o
u
s dem
a
nd rat
e
Evaluation Warning : The document was created with Spire.PDF for Python.
I
S
SN
:
2
088
-87
08
I
J
ECE Vo
l. 5
,
N
o
. 4
,
Au
gu
st 2
015
:
74
2
–
74
9
7
47
Figure 5 s
h
ows the output of calculator as
λ
/
PFD i
n
va
r
i
ous dem
a
nd r
a
t
e
. From
t
h
e out
p
u
t
of
cal
cul
a
t
o
r, l
o
w
dem
a
nd app
r
o
ach j
u
st
su
ffi
ci
ent
i
f
use
d
i
n
t
h
e ra
nge
of
de
m
a
nd l
e
ss t
h
an
0.5 /
y
ear
. It
co
ul
d
be
seen i
n
Fi
gu
re
6 as
enl
a
r
g
em
ent
vi
e
w
fr
om
Fi
gu
re
5.
Fi
gu
re
6.
The
r
a
nge
o
f
dem
a
nd
rat
e
su
ffi
ci
e
n
t
fo
r l
o
w
dem
a
nd
The differe
n
t value of
λ
b
e
t
w
een
h
i
gh
d
e
m
a
n
d
an
d
low d
e
man
d
app
r
o
a
ch
will b
e
o
ccured
at d
e
m
a
n
d
rat
e
5.
1/
y
ear.
I
n
a
not
her
w
o
r
d
i
f
l
o
w
dem
a
nd
ap
pr
oac
h
i
s
use
d
, st
a
r
t
f
r
o
m
t
h
e dem
a
nd
rat
e
5.
1/
y
ear,
t
h
e l
o
w
d
e
m
a
n
d
appro
a
ch
will p
r
ov
id
e h
i
gh
er SIL
targ
et
th
an
h
i
gh
de
m
a
n
d
ap
pro
a
ch
.
Fi
gu
re
7 s
h
ow
s t
h
e
di
f
f
ere
n
t
col
o
ur
f
o
r
SI
L
1
(l
i
g
t
h
bl
ue)
and
S
I
L
2
(y
el
l
o
w
)
.
It
seem
that
λ
val
u
e
fr
om
hi
gh dem
a
nd a
p
p
r
o
ach
al
way
s
l
a
y
at
SIL 1
.
Ho
we
v
e
r,
λ
val
u
e f
r
o
m
l
o
w dem
a
nd appr
oac
h
l
a
y
at
SIL 1
and S
I
L
2. I
n
t
h
i
s
case, en
gi
n
eer sh
o
u
l
d
us
e
hi
g
h
dem
a
nd
app
r
oach st
rat
fr
o Hi
s m
o
re suf
f
i
c
i
e
nt
t
o
use
hi
g
h
dem
a
nd eq
uat
i
on
t
h
at
resul
t
i
n
S
I
L
1 l
o
we
r t
h
an
hi
gh
dem
a
nd
ap
p
r
oac
h
de
m
a
nd
rat
e
5
.
1/
y
ear.
Fi
gu
re
7.
Er
ro
r
bet
w
ee
n
hi
g
h
dem
a
nd an
d l
o
w
dem
a
nd ap
p
r
oac
h
(di
ffe
ren
t
resul
t
of
SI
L)
Evaluation Warning : The document was created with Spire.PDF for Python.
I
J
ECE
I
S
SN
:
208
8-8
7
0
8
H
and
lin
g
Lo
w a
n
d
H
i
gh
D
e
ma
nd
Mod
e
on
Sa
fety
In
strum
e
n
t
ed
Fun
c
tion
(
T
ot
ok
R.
Bi
ya
n
t
o)
74
8
Using the
same case m
e
ntioned above a
n
d the dem
a
nd
r
a
t
e
22/
y
ear
, t
h
e di
f
f
ere
n
t
S
I
L
t
a
rget
fr
om
b
o
t
h
app
r
o
a
ch
are shown
in
Fig
u
re 8
.
Th
e
h
i
g
h
e
r SIL
will ach
iev
e
d
if th
e
calcu
latio
n
of
SIL
u
s
e low d
e
man
d
equat
i
o
n i
n
hi
gh
dem
a
nd ap
pl
i
cat
i
on. T
h
e
st
art
i
ng p
o
i
n
of di
f
f
ere
n
t
val
u
e o
f
l
a
m
d
a or SI
L de
pe
nds
o
n
hazardous
eve
n
t freque
ncy
(H), PFDa
vg of ERRF a
n
d test interval (T
).
As m
e
t
i
oned
bef
o
re
hi
ger
S
I
L i
n
c
r
eases s
a
fet
y
cost
. Si
n
ce, t
h
e
hi
g
h
d
e
m
a
nd i
s
ue
i
s
new
i
s
ue i
n
recent tim
e, the engi
neer
s
hould
be care
f
ull to determ
ined SIL target for vari
ous
pla
n
t dem
a
nd by re
c
o
rding
the pla
n
t trip or s
hut
down e
v
e
n
t pe
r year for
each e
qui
pm
ents.
Fi
gu
re
8.
Di
f
f
e
r
ent
res
u
l
t
of
S
I
L
on
dem
a
nd
rat
e
2
2
/
y
ear
4.
CO
NCL
USI
O
N
The val
u
e of dem
a
nd
rat
e
s
h
o
u
l
d
be det
e
rm
i
n
ed
fi
rst
b
a
sed on pl
ant
m
a
i
n
t
e
nance pl
ani
n
g
a
n
d
act
i
v
i
t
y
dat
a
. The
di
ffe
re
nt
val
u
e
of
l
a
m
d
a or
SIL
de
pe
n
d
s
on
dem
a
nd
rat
e
(
D
),
haza
r
d
o
u
s e
v
e
n
t
f
r
e
que
ncy
(H
), P
F
Da
v
g
o
f
ERRF an
d te
st interval (T
).
From
the
st
udy
case, i
t
can be
concl
ude
d t
h
a
t
at
t
h
e dem
a
n
d
rat
e
lo
wer th
an
0
.
5
/
year it will sufficien
t
to
u
s
e lo
w d
e
m
a
n
d
app
r
o
a
ch
, and
at
d
e
m
a
n
d
rate ab
ov
e
5
.
1
/
year t
h
e l
o
w
an
d h
i
g
h
d
e
m
a
n
d
appro
a
ch
will p
r
ov
id
e d
i
ffren
t
SIL targ
et
.
ACKNOWLE
DGE
M
ENTS
Th
e au
tho
r
s
g
r
atefu
lly th
an
k
Sepu
luh
Nop
e
m
b
er In
stitu
te o
f
Techo
l
og
y (ITS)
Su
rab
a
ya for
p
r
ov
id
ing
t
h
e facilities fo
r con
d
u
c
ting
th
is research.
REFERE
NC
ES
[1]
A.G. King, "SIL determinatio
n
:
Recognising
and handling hi
g
h
demand mode scen
arios",
Process Safety an
d
Environmenta
l P
r
otection
,
vo
l. 9
2
, pp
. 324-328
,
7// 2014
.
[2]
R.W. Johnson,
"Bey
ond-
compliance
uses of HAZOP/LOPA
studies",
Jour
nal of L
o
s
s
Pr
eventi
on in the Pr
oce
s
s
Industries,
vol. 2
3
, pp
. 727-733
,
11// 2010
.
[3]
P. Hokstad, "Demand rate
and r
i
sk reduction fo
r safety
i
n
s
t
r
u
me
n
t
e
d
sy
st
e
m
s
"
,
Reliab
ili
ty Eng
i
neering
&
System
Safet
y,
vol. 127,
pp. 12-20
, 7// 20
14.
[4]
Y. Misum
i
and
Y. Sato, "Estim
a
tion of
ave
r
age
hazardous-e
v
e
nt
-frequenc
y
for al
loca
tion
of
safe
t
y
-in
t
egr
i
t
y
leve
l
s
",
Reliab
ility Engin
eering
&
System Safety,
vol. 66
,
pp. 135-144
, 11// 1999.
[5]
I. 61508
,
"Part 1: G
e
neral r
e
quir
e
ments Gene
ral r
e
quir
e
ments: Fuctin
io
nal Saf
e
ty of
Electrical/Electr
onic/Pr
ogrammable Electron
ic
S
a
fety
-R
elat
ed
S
y
stem", vol. Part
1, 1998
.
[6]
K. TA, "Hazop
and Hazan: id
en
tif
y
i
ng
and
a
sse
s
s
ing proc
e
ss industry
ha
z
a
rds",
Rugby, UK: Institution
of Chemical
Engineers,
pp. 1
-
223, 1999
.
[7]
ISO/IEC, "Guid
e
51", 1997.
Evaluation Warning : The document was created with Spire.PDF for Python.
I
S
SN
:
2
088
-87
08
I
J
ECE Vo
l. 5
,
N
o
. 4
,
Au
gu
st 2
015
:
74
2
–
74
9
7
49
BIOGRAP
HI
ES OF
AUTH
ORS
Totok R. Biyanto
(TRB)
is senior lectur
er at Instrumen
t
ation
,
Process
Control and
Optimizatio
n, D
e
partment of
Engineer
ing Ph
y
s
ic
s, Faculty
of
Industrial Engin
eering
,
Institu
t
Teknologi Sepu
luh Nopember, Surabay
a
, Ind
onesi
a. He received his Bach
elor degree in
Engineering Ph
ysics from
Institut Teknolog
i Sep
u
luh Nopem
b
er,
Surabay
a
, Indon
esia,
and Ph.D
in Chem
ic
al
E
ngineer
ing from
Univers
i
t
i
T
e
k
nologi P
e
tron
as
,
M
a
la
ys
i
a
.
His
res
ear
ch
and
tea
c
hing int
e
rest
s are in at Instr
u
m
e
ntation
,
Process Control an
d Optim
ization
,
Green building
,
Energ
y
effisiency
and conservation, heat
integr
at
ion, and plan
t design. He has published resear
ch
papers in
var
i
ou
s journals
and C
onferences.
F
r
anky
r
e
c
e
ive
d
his Bach
elor
degree
in
Engin
eering
Ph
y
s
i
c
s f
r
om
Institut T
e
k
nologi Sepuluh
Nopember, Surabay
a
, Indon
esia. His r
e
search
in
ter
e
sts ar
e in safety
,
instru
mentations an
d
control. He has
published r
e
sear
ch pap
e
rs
in
var
i
ous
journals and Conferences.
Hendra Cordova,
is senior lecturer at Instrumentatio
n
,
Process Control and Optim
ization
,
Department of
Engineering Phy
s
ics
,
Faculty
of Industrial Engineer
ing, Institut Teknolog
i
Sepuluh Nopember, Surab
a
y
a
,
Indonesia. He r
ece
ived h
i
s Bachelor
degree
in Engineering
Ph
y
s
ics from
In
stitut
Teknolog
i
Sepuluh Nopem
b
er,
Surab
a
y
a
, I
ndonesia, and M
a
ster d
e
gree in
Engineering Ph
y
s
ics from Instit
ut Teknologi B
a
ndung, Indon
esia.
His resear
ch
and teaching
inter
e
sts are in
Instrum
e
ntatio
ns and control.
He has published resear
ch papers in various
journals and
Co
nferences.
Yerr
y S
u
s
atio
is senior lecturer at Instrumentati
on, Process Control and Optimizatio
n
,
Department of
Engineering Phy
s
ics
,
Faculty
of Industrial Engineer
ing, Institut Teknolog
i
Sepuluh Nopember, Surab
a
y
a
,
Indonesia. He r
ece
ived h
i
s Bachelor
degree
in Engineering
Ph
y
s
ics from
In
stitut
Teknolog
i
Sepuluh Nopem
b
er,
Surab
a
y
a
, I
ndonesia, and M
a
ster d
e
gree in
Mechani
cal
Eng
i
neer
ing from
In
stitut
Teknolog
i
Sepuluh Nopem
b
er, Surabay
a
, Indonesia. His
res
earch
and
t
e
a
c
hing
inter
e
s
t
s
a
r
e in
a
c
ous
tic
an
d
vibration. He
has publishe
d
re
s
earch p
a
pers
in
various journ
a
ls
and Confer
ences.
Ridho Bay
u
aji
is senior lectur
er at Dep
a
rtment of
Civil Eng
i
neer
ing, Facu
lty
of Civil and
Planing Engin
e
ering, Institut
Teknologi Sepuluh
Nopember, Sura
bay
a
, Indonesia. He r
e
ceived
his Bachelor deg
r
ee in Civi
l Engi
neering from
Institut T
e
knologi
Sepuluh Nopember, Surab
a
y
a
,
Indonesia,
and Ph.D in Civil E
ngineer
ing from
Universiti T
e
k
nologi Petronas, Malay
s
ia. His
res
earch
and t
e
aching
inter
e
s
t
s
are in gr
een
material and
co
nstructions. He has published
research
pap
e
rs in various
journals and Conferences.
Evaluation Warning : The document was created with Spire.PDF for Python.