<s>
In	O
software	O
project	O
management	O
,	O
software	O
testing	O
,	O
and	O
software	B-General_Concept
engineering	I-General_Concept
,	O
verification	B-Application
and	I-Application
validation	I-Application
(	O
V&V	O
)	O
is	O
the	O
process	O
of	O
checking	O
that	O
a	O
software	O
system	O
meets	O
specifications	O
and	O
requirements	O
so	O
that	O
it	O
fulfills	O
its	O
intended	O
purpose	O
.	O
</s>
<s>
It	O
may	O
also	O
be	O
referred	O
to	O
as	O
software	B-Application
quality	I-Application
control	I-Application
.	O
</s>
<s>
On	O
the	O
other	O
hand	O
,	O
software	B-Application
validation	I-Application
is	O
:	O
"	O
Was	O
X	O
what	O
we	O
should	O
have	O
built	O
?	O
</s>
<s>
Verification	B-Application
and	I-Application
validation	I-Application
are	O
not	O
the	O
same	O
thing	O
,	O
although	O
they	O
are	O
often	O
confused	O
.	O
</s>
<s>
Ideally	O
,	O
formal	B-Architecture
methods	I-Architecture
provide	O
a	O
mathematical	O
guarantee	O
that	O
software	O
meets	O
its	O
specifications	O
.	O
</s>
<s>
(	O
Adapted	O
from	O
"	O
Verification	B-Application
and	I-Application
Validation	I-Application
in	O
plain	O
English	O
"	O
(	O
Lake	O
INCOSE	O
1999	O
)	O
.	O
)	O
</s>
<s>
Software	B-Application
validation	I-Application
checks	O
that	O
the	O
software	O
product	O
satisfies	O
or	O
fits	O
the	O
intended	O
use	O
(	O
high-level	O
checking	O
)	O
,	O
i.e.	O
,	O
the	O
software	O
meets	O
the	O
user	O
requirements	O
,	O
not	O
as	O
specification	O
artifacts	O
or	O
as	O
needs	O
of	O
those	O
who	O
will	O
operate	O
the	O
software	O
only	O
;	O
but	O
,	O
as	O
the	O
needs	O
of	O
all	O
the	O
stakeholders	O
(	O
such	O
as	O
users	O
,	O
operators	O
,	O
administrators	O
,	O
managers	O
,	O
investors	O
,	O
etc	O
.	O
)	O
.	O
</s>
<s>
There	O
are	O
two	O
ways	O
to	O
perform	O
software	B-Application
validation	I-Application
:	O
internal	O
and	O
external	O
.	O
</s>
<s>
During	O
internal	O
software	B-Application
validation	I-Application
,	O
it	O
is	O
assumed	O
that	O
the	O
goals	O
of	O
the	O
stakeholders	O
were	O
correctly	O
understood	O
and	O
that	O
they	O
were	O
expressed	O
in	O
the	O
requirement	O
artifacts	O
precisely	O
and	O
comprehensively	O
.	O
</s>
<s>
Software	B-Application
Validation	I-Application
:	O
The	O
process	O
of	O
evaluating	O
software	O
during	O
or	O
at	O
the	O
end	O
of	O
the	O
development	O
process	O
to	O
determine	O
whether	O
it	O
satisfies	O
specified	O
requirements	O
.	O
</s>
<s>
Validation	O
during	O
the	O
software	O
development	O
process	O
can	O
be	O
seen	O
as	O
a	O
form	O
of	O
User	O
Requirements	O
Specification	O
validation	O
;	O
and	O
,	O
that	O
at	O
the	O
end	O
of	O
the	O
development	O
process	O
is	O
equivalent	O
to	O
Internal	O
and/or	O
External	O
Software	B-Application
validation	I-Application
.	O
</s>
<s>
In	O
other	O
words	O
,	O
software	O
verification	O
ensures	O
that	O
the	O
output	O
of	O
each	O
phase	O
of	O
the	O
software	O
development	O
process	O
effectively	O
carry	O
out	O
what	O
its	O
corresponding	O
input	O
artifact	O
specifies	O
(	O
requirement	O
->	O
design	O
->	O
software	O
product	O
)	O
,	O
while	O
software	B-Application
validation	I-Application
ensures	O
that	O
the	O
software	O
product	O
meets	O
the	O
needs	O
of	O
all	O
the	O
stakeholders	O
(	O
therefore	O
,	O
the	O
requirement	O
specification	O
was	O
correctly	O
and	O
accurately	O
expressed	O
in	O
the	O
first	O
place	O
)	O
.	O
</s>
<s>
Software	B-Application
validation	I-Application
ensures	O
that	O
"	O
you	O
built	O
the	O
right	O
thing	O
"	O
and	O
confirms	O
that	O
the	O
product	O
,	O
as	O
provided	O
,	O
fulfills	O
the	O
intended	O
use	O
and	O
goals	O
of	O
the	O
stakeholders	O
.	O
</s>
<s>
Both	O
verification	B-Application
and	I-Application
validation	I-Application
are	O
related	O
to	O
the	O
concepts	O
of	O
quality	O
and	O
of	O
software	O
quality	O
assurance	O
.	O
</s>
<s>
By	O
themselves	O
,	O
verification	B-Application
and	I-Application
validation	I-Application
do	O
not	O
guarantee	O
software	O
quality	O
;	O
planning	O
,	O
traceability	B-Device
,	O
configuration	O
management	O
and	O
other	O
aspects	O
of	O
software	B-General_Concept
engineering	I-General_Concept
are	O
required	O
.	O
</s>
<s>
M&S	O
Verification	O
is	O
the	O
process	O
of	O
determining	O
that	O
a	O
computer	B-Application
model	I-Application
,	O
simulation	O
,	O
or	O
federation	O
of	O
models	O
and	O
simulations	O
implementations	O
and	O
their	O
associated	O
data	O
accurately	O
represent	O
the	O
developer	O
's	O
conceptual	O
description	O
and	O
specifications	O
.	O
</s>
<s>
This	O
stands	O
in	O
contrast	O
to	O
software	B-Application
validation	I-Application
.	O
</s>
<s>
In	O
mission-critical	O
software	O
systems	O
,	O
formal	B-Architecture
methods	I-Architecture
may	O
be	O
used	O
to	O
ensure	O
the	O
correct	O
operation	O
of	O
a	O
system	O
.	O
</s>
<s>
These	O
formal	B-Architecture
methods	I-Architecture
can	O
prove	O
costly	O
,	O
however	O
,	O
representing	O
as	O
much	O
as	O
80	O
percent	O
of	O
total	O
software	O
design	O
cost	O
.	O
</s>
<s>
Independent	O
Software	B-Application
Verification	I-Application
and	I-Application
Validation	I-Application
(	O
ISVV	O
)	O
is	O
targeted	O
at	O
safety-critical	B-Application
software	O
systems	O
and	O
aims	O
to	O
increase	O
the	O
quality	O
of	O
software	O
products	O
,	O
thereby	O
reducing	O
risks	O
and	O
costs	O
through	O
the	O
operational	O
life	O
of	O
the	O
software	O
.	O
</s>
<s>
ISVV	O
goes	O
beyond	O
"	O
traditional	O
"	O
verification	B-Application
and	I-Application
validation	I-Application
techniques	O
,	O
applied	O
by	O
development	O
teams	O
.	O
</s>
<s>
ISVV	O
derives	O
from	O
the	O
application	O
of	O
IV&V	O
(	O
Independent	O
Verification	B-Application
and	I-Application
Validation	I-Application
)	O
to	O
the	O
software	O
.	O
</s>
<s>
IV&V	O
is	O
mentioned	O
in	O
DO-178B	O
,	O
ISO/IEC	O
12207	O
and	O
formalized	O
in	O
IEEE	B-Application
1012	I-Application
.	O
</s>
<s>
Initially	O
in	O
2004-2005	O
,	O
a	O
European	O
consortium	O
led	O
by	O
the	O
European	O
Space	O
Agency	O
,	O
and	O
composed	O
by	O
DNV	O
,	O
Critical	O
Software	O
SA	O
,	O
Terma	O
and	O
CODA	O
SciSys	O
plc	O
created	O
the	O
first	O
version	O
of	O
a	O
guide	O
devoted	O
to	O
ISVV	O
,	O
called	O
"	O
ESA	O
Guide	O
for	O
Independent	O
Verification	B-Application
and	I-Application
Validation	I-Application
"	O
with	O
support	O
from	O
other	O
organizations	O
.	O
</s>
<s>
This	O
guide	O
covers	O
the	O
methodologies	O
applicable	O
to	O
all	O
the	O
software	B-General_Concept
engineering	I-General_Concept
phases	O
in	O
what	O
concerns	O
ISVV	O
.	O
</s>
