<s>
Generalized	B-Operating_System
Foreground-Background	I-Operating_System
(	O
FB	O
)	O
,	O
also	O
known	O
as	O
Least	O
Attained	O
Service	O
(	O
LAS	O
)	O
is	O
a	O
scheduling	O
policy	O
.	O
</s>
<s>
Similarly	O
to	O
SRPT	B-Operating_System
,	O
the	O
aim	O
of	O
FB	O
is	O
to	O
improve	O
the	O
performance	O
of	O
a	O
system	O
,	O
specifically	O
mean	O
response	O
time	O
.	O
</s>
<s>
While	O
SRPT	B-Operating_System
is	O
optimal	O
it	O
is	O
more	O
difficult	O
to	O
apply	O
in	O
practice	O
as	O
it	O
requires	O
accurate	O
estimations	O
of	O
the	O
service	O
time	O
of	O
each	O
request	O
.	O
</s>
<s>
In	O
contrast	O
,	O
FB	O
does	O
not	O
require	O
estimations	O
of	O
service	O
times	O
,	O
making	O
it	O
more	O
practical	O
but	O
also	O
less	O
performing	O
than	O
SRPT	B-Operating_System
.	O
</s>
