<s>
Performance	B-General_Concept
engineering	I-General_Concept
encompasses	O
the	O
techniques	O
applied	O
during	O
a	O
systems	B-General_Concept
development	I-General_Concept
life	I-General_Concept
cycle	I-General_Concept
to	O
ensure	O
the	O
non-functional	O
requirements	O
for	O
performance	O
(	O
such	O
as	O
throughput	O
,	O
latency	O
,	O
or	O
memory	B-General_Concept
usage	O
)	O
will	O
be	O
met	O
.	O
</s>
<s>
It	O
may	O
be	O
alternatively	O
referred	O
to	O
as	O
systems	B-General_Concept
performance	I-General_Concept
engineering	I-General_Concept
within	O
systems	O
engineering	O
,	O
and	O
software	B-General_Concept
performance	I-General_Concept
engineering	I-General_Concept
or	O
application	B-Application
performance	I-Application
engineering	I-Application
within	O
software	B-General_Concept
engineering	I-General_Concept
.	O
</s>
<s>
As	O
the	O
connection	O
between	O
application	O
success	O
and	O
business	O
success	O
continues	O
to	O
gain	O
recognition	O
,	O
particularly	O
in	O
the	O
mobile	O
space	O
,	O
application	B-Application
performance	I-Application
engineering	I-Application
has	O
taken	O
on	O
a	O
preventive	O
and	O
perfective	O
role	O
within	O
the	O
software	O
development	O
life	O
cycle	O
.	O
</s>
<s>
The	O
term	O
performance	B-General_Concept
engineering	I-General_Concept
encompasses	O
more	O
than	O
just	O
the	O
software	O
and	O
supporting	O
infrastructure	O
,	O
and	O
as	O
such	O
the	O
term	O
performance	B-General_Concept
engineering	I-General_Concept
is	O
preferable	O
from	O
a	O
macro	O
view	O
.	O
</s>
<s>
Performance	B-General_Concept
engineering	I-General_Concept
has	O
become	O
a	O
separate	O
discipline	O
at	O
a	O
number	O
of	O
large	O
corporations	O
,	O
with	O
tasking	O
separate	O
but	O
parallel	O
to	O
systems	O
engineering	O
.	O
</s>
<s>
It	O
is	O
pervasive	O
,	O
involving	O
people	O
from	O
multiple	O
organizational	O
units	O
;	O
but	O
predominantly	O
within	O
the	O
information	B-General_Concept
technology	I-General_Concept
organization	O
.	O
</s>
<s>
However	O
,	O
if	O
the	O
phases	O
of	O
the	O
rational	B-Application
unified	I-Application
process	I-Application
(	O
RUP	O
)	O
are	O
used	O
as	O
a	O
framework	O
,	O
then	O
the	O
activities	O
will	O
occur	O
as	O
follows	O
:	O
</s>
<s>
During	O
this	O
defining	O
phase	O
,	O
the	O
critical	O
business	O
processes	O
are	O
decomposed	O
to	O
critical	O
use	B-Architecture
cases	I-Architecture
.	O
</s>
<s>
These	O
are	O
the	O
use	B-Architecture
cases	I-Architecture
that	O
will	O
be	O
subjected	O
to	O
script	O
driven	O
performance	O
testing	O
.	O
</s>
<s>
The	O
type	O
of	O
requirements	O
that	O
relate	O
to	O
performance	B-General_Concept
engineering	I-General_Concept
are	O
the	O
non-functional	O
requirements	O
,	O
or	O
NFR	O
.	O
</s>
<s>
Specify	O
an	O
automated	O
multi-user	O
capable	O
script-driven	O
end-to-end	O
tool	O
for	O
the	O
development/component	O
unit	O
test	O
environment	O
;	O
this	O
is	O
used	O
to	O
execute	O
screen-driven	O
use	B-Architecture
cases	I-Architecture
.	O
</s>
<s>
This	O
team	O
will	O
execute	O
performance	O
testing	O
against	O
test	O
cases	O
,	O
validating	O
that	O
the	O
critical	O
use	B-Architecture
cases	I-Architecture
conform	O
to	O
the	O
specified	O
non-functional	O
requirements	O
.	O
</s>
<s>
The	O
data	O
gathered	O
,	O
and	O
the	O
analysis	O
,	O
will	O
be	O
fed	O
back	O
to	O
the	O
group	O
that	O
does	O
performance	B-Device
tuning	I-Device
.	O
</s>
<s>
If	O
performance	B-General_Concept
engineering	I-General_Concept
has	O
been	O
properly	O
applied	O
at	O
each	O
iteration	O
and	O
phase	O
of	O
the	O
project	O
to	O
this	O
point	O
,	O
hopefully	O
this	O
will	O
be	O
sufficient	O
to	O
enable	O
the	O
system	O
to	O
receive	O
performance	O
certification	O
.	O
</s>
<s>
However	O
,	O
if	O
for	O
some	O
reason	O
(	O
perhaps	O
proper	O
performance	B-General_Concept
engineering	I-General_Concept
working	O
practices	O
were	O
not	O
applied	O
)	O
there	O
are	O
tests	O
that	O
cannot	O
be	O
tuned	O
into	O
compliance	O
,	O
then	O
it	O
will	O
be	O
necessary	O
to	O
return	O
portions	O
of	O
the	O
system	O
to	O
development	O
for	O
refactoring	O
.	O
</s>
<s>
In	O
the	O
operational	O
domain	O
(	O
post	O
production	O
deployment	O
)	O
performance	B-General_Concept
engineering	I-General_Concept
focuses	O
primarily	O
within	O
three	O
areas	O
:	O
service	O
level	O
management	O
,	O
capacity	O
management	O
,	O
and	O
problem	O
management	O
.	O
</s>
<s>
In	O
the	O
service	O
level	O
management	O
area	O
,	O
performance	B-General_Concept
engineering	I-General_Concept
is	O
concerned	O
with	O
service	O
level	O
agreements	O
and	O
the	O
associated	O
systems	O
monitoring	O
that	O
serves	O
to	O
validate	O
service	O
level	O
compliance	O
,	O
detect	O
problems	O
,	O
and	O
identify	O
trends	O
.	O
</s>
<s>
For	O
capacity	O
management	O
,	O
performance	B-General_Concept
engineering	I-General_Concept
focuses	O
on	O
ensuring	O
that	O
the	O
systems	O
will	O
remain	O
within	O
performance	O
compliance	O
.	O
</s>
<s>
Capacity	O
management	O
is	O
charged	O
with	O
ensuring	O
that	O
additional	O
capacity	O
is	O
added	O
in	O
advance	O
of	O
that	O
point	O
(	O
additional	O
CPUs	O
,	O
more	O
memory	B-General_Concept
,	O
new	O
database	O
indexing	O
,	O
et	O
cetera	O
)	O
so	O
that	O
the	O
trend	O
lines	O
are	O
reset	O
and	O
the	O
system	O
will	O
remain	O
within	O
the	O
specified	O
performance	O
range	O
.	O
</s>
<s>
Within	O
the	O
problem	O
management	O
domain	O
,	O
the	O
performance	B-General_Concept
engineering	I-General_Concept
practices	O
are	O
focused	O
on	O
resolving	O
the	O
root	O
cause	O
of	O
performance	O
related	O
problems	O
.	O
</s>
<s>
It	O
is	O
possible	O
to	O
establish	O
service	O
level	O
agreements	O
at	O
the	O
use	B-Architecture
case	I-Architecture
level	O
.	O
</s>
<s>
It	O
enables	O
the	O
ability	O
to	O
track	O
trends	O
over	O
time	O
,	O
such	O
as	O
the	O
impact	O
of	O
increasing	O
user	O
loads	O
and	O
growing	O
data	O
sets	O
on	O
use	B-Architecture
case	I-Architecture
level	O
performance	O
.	O
</s>
<s>
This	O
functionality	O
,	O
properly	O
implemented	O
,	O
will	O
enable	O
predicting	O
when	O
a	O
given	O
application	O
undergoing	O
gradually	O
increasing	O
user	O
loads	O
and	O
growing	O
data	O
sets	O
will	O
exceed	O
the	O
specified	O
non	O
functional	O
performance	O
requirements	O
for	O
a	O
given	O
use	B-Architecture
case	I-Architecture
.	O
</s>
