<s>
Integration	O
DEFinition	O
for	O
information	B-Application
modeling	I-Application
(	O
IDEF1X	B-Application
)	O
is	O
a	O
data	B-Language
modeling	I-Language
language	I-Language
for	O
the	O
development	O
of	O
semantic	O
data	O
models	O
.	O
</s>
<s>
IDEF1X	B-Application
is	O
used	O
to	O
produce	O
a	O
graphical	O
information	B-Application
model	I-Application
which	O
represents	O
the	O
structure	O
and	O
semantics	B-Application
of	O
information	O
within	O
an	O
environment	O
or	O
system	O
.	O
</s>
<s>
IDEF1X	B-Application
permits	O
the	O
construction	O
of	O
semantic	O
data	O
models	O
which	O
may	O
serve	O
to	O
support	O
the	O
management	O
of	O
data	O
as	O
a	O
resource	O
,	O
the	O
integration	O
of	O
information	O
systems	O
,	O
and	O
the	O
building	O
of	O
computer	O
databases	O
.	O
</s>
<s>
This	O
standard	O
is	O
part	O
of	O
the	O
IDEF	O
family	O
of	O
modeling	B-Language
languages	I-Language
in	O
the	O
field	O
of	O
software	B-General_Concept
engineering	I-General_Concept
.	O
</s>
<s>
A	O
data	B-Application
modeling	I-Application
technique	O
is	O
used	O
to	O
model	O
data	O
in	O
a	O
standard	O
,	O
consistent	O
and	O
predictable	O
manner	O
in	O
order	O
to	O
manage	O
it	O
as	O
a	O
resource	O
.	O
</s>
<s>
Such	O
projects	O
include	O
the	O
incorporation	O
of	O
a	O
data	B-Application
modeling	I-Application
technique	O
into	O
a	O
methodology	O
,	O
managing	O
data	O
as	O
a	O
resource	O
,	O
integrating	O
information	O
systems	O
,	O
or	O
designing	O
computer	O
databases	O
.	O
</s>
<s>
The	O
primary	O
objectives	O
of	O
the	O
IDEF1X	B-Application
standard	O
are	O
to	O
provide	O
:	O
</s>
<s>
A	O
principal	O
objective	O
of	O
IDEF1X	B-Application
is	O
to	O
support	O
integration	O
.	O
</s>
<s>
The	O
approach	O
to	O
integration	O
focuses	O
on	O
the	O
capture	O
,	O
management	O
,	O
and	O
use	O
of	O
a	O
single	O
semantic	O
definition	O
of	O
the	O
data	O
resource	O
referred	O
to	O
as	O
a	O
“	O
conceptual	O
schema.	O
”	O
The	O
“	O
conceptual	B-Application
schema	I-Application
”	O
provides	O
a	O
single	O
integrated	O
definition	O
of	O
the	O
data	O
within	O
an	O
enterprise	O
which	O
is	O
not	O
biased	O
toward	O
any	O
single	O
application	O
of	O
data	O
and	O
is	O
independent	O
of	O
how	O
the	O
data	O
is	O
physically	O
stored	O
or	O
accessed	O
.	O
</s>
<s>
The	O
primary	O
objective	O
of	O
this	O
conceptual	B-Application
schema	I-Application
is	O
to	O
provide	O
a	O
consistent	O
definition	O
of	O
the	O
meanings	O
of	O
and	O
interrelationships	O
between	O
data	O
that	O
can	O
be	O
used	O
to	O
integrate	O
,	O
share	O
,	O
and	O
manage	O
the	O
integrity	O
of	O
data	O
.	O
</s>
<s>
A	O
conceptual	B-Application
schema	I-Application
must	O
have	O
three	O
important	O
characteristics	O
:	O
</s>
<s>
The	O
initial	O
approach	O
to	O
IDEF	O
information	B-Application
modeling	I-Application
(	O
IDEF1	B-Application
)	O
was	O
published	O
by	O
the	O
ICAM	O
program	O
in	O
1981	O
,	O
based	O
on	O
current	O
research	O
and	O
industry	O
needs	O
.	O
</s>
<s>
The	O
theoretical	O
roots	O
for	O
this	O
approach	O
stemmed	O
from	O
the	O
early	O
work	O
of	O
Edgar	O
F	O
.	O
Codd	O
on	O
Relational	B-Architecture
model	I-Architecture
theory	O
and	O
Peter	O
Chen	O
on	O
the	O
entity-relationship	B-Architecture
model	I-Architecture
.	O
</s>
<s>
The	O
initial	O
IDEF1	B-Application
technique	O
was	O
based	O
on	O
the	O
work	O
of	O
Dr	O
R	O
.	O
R	O
.	O
Brown	O
and	O
Mr	O
T	O
.	O
L	O
.	O
Ramey	O
of	O
Hughes	O
Aircraft	O
and	O
Mr	O
D	O
.	O
S	O
.	O
Coleman	O
of	O
D	O
.	O
Appleton	O
Company	O
(	O
DACOM	O
)	O
,	O
with	O
critical	O
review	O
and	O
influence	O
by	O
Charles	O
Bachman	O
,	O
Peter	O
Chen	O
,	O
Dr	O
M	O
.	O
A	O
.	O
Melkanoff	O
,	O
and	O
Dr	O
G.M.	O
</s>
<s>
As	O
a	O
result	O
of	O
this	O
project	O
,	O
and	O
industry	O
experience	O
,	O
the	O
need	O
for	O
an	O
enhanced	O
technique	O
for	O
information	B-Application
modeling	I-Application
was	O
recognized	O
.	O
</s>
<s>
From	O
the	O
point	O
of	O
view	O
of	O
the	O
contract	O
administrators	O
of	O
the	O
Air	O
Force	O
IDEF	O
program	O
,	O
IDEF1X	B-Application
was	O
a	O
result	O
of	O
the	O
ICAM	O
IISS-6201	O
project	O
and	O
was	O
further	O
extended	O
by	O
the	O
IISS-6202	O
project	O
.	O
</s>
<s>
To	O
satisfy	O
the	O
data	B-Application
modeling	I-Application
enhancement	O
requirements	O
that	O
were	O
identified	O
in	O
the	O
IISS-6202	O
project	O
,	O
a	O
sub-contractor	O
,	O
DACOM	O
,	O
obtained	O
a	O
license	O
to	O
the	O
Logical	O
Database	O
Design	O
Technique	O
(	O
LDDT	O
)	O
and	O
its	O
supporting	O
software	O
(	O
ADAM	O
)	O
.	O
</s>
<s>
From	O
the	O
point	O
of	O
view	O
of	O
the	O
technical	O
content	O
of	O
the	O
modeling	O
technique	O
,	O
IDEF1X	B-Application
is	O
a	O
renaming	O
of	O
LDDT	O
.	O
</s>
<s>
Since	O
September	O
2012	O
,	O
IDEF1X	B-Application
is	O
part	O
of	O
the	O
international	O
standard	O
ISO/IEC/IEEE	O
31320-2:2012	O
.	O
</s>
<s>
The	O
standard	O
describes	O
the	O
syntax	O
and	O
semantics	B-Application
of	O
IDEF1X97	O
,	O
which	O
consists	O
of	O
two	O
conceptual	O
modeling	B-Language
languages	I-Language
:	O
a	O
“	O
key-style	O
”	O
language	B-Language
downward	O
compatible	O
with	O
FIPS	O
184	O
,	O
which	O
supports	O
relational	O
and	O
extended	O
relational	O
databases	O
,	O
and	O
a	O
newer	O
“	O
identity-style	O
”	O
language	B-Language
suitable	O
for	O
object	O
databases	O
and	O
object-oriented	O
modeling	O
.	O
</s>
<s>
The	O
logical	O
database	O
design	O
technique	O
(	O
LDDT	O
)	O
had	O
been	O
developed	O
in	O
1982	O
by	O
Robert	O
G	O
.	O
Brown	O
of	O
The	O
Database	O
Design	O
Group	O
entirely	O
outside	O
the	O
IDEF	O
program	O
and	O
with	O
no	O
knowledge	O
of	O
IDEF1	B-Application
.	O
</s>
<s>
Nevertheless	O
,	O
the	O
central	O
goal	O
of	O
IDEF1	B-Application
and	O
LDDT	O
was	O
the	O
same	O
:	O
to	O
produce	O
a	O
database-neutral	O
model	O
of	O
the	O
persistent	O
information	O
needed	O
by	O
an	O
enterprise	O
by	O
modeling	O
the	O
real-world	O
entities	O
involved	O
.	O
</s>
<s>
LDDT	O
combined	O
elements	O
of	O
the	O
relational	B-Architecture
data	I-Architecture
model	I-Architecture
,	O
the	O
E-R	B-Architecture
model	I-Architecture
,	O
and	O
data	O
generalization	O
in	O
a	O
way	O
specifically	O
intended	O
to	O
support	O
data	B-Application
modeling	I-Application
and	O
the	O
transformation	O
of	O
the	O
data	O
models	O
into	O
database	O
designs	O
.	O
</s>
<s>
Early	O
LDDT	O
models	O
were	O
transformed	O
into	O
database	O
designs	O
for	O
IBM	O
's	O
hierarchical	O
database	O
,	O
IMS	B-Application
.	O
</s>
<s>
The	O
LDDT	O
software	O
,	O
ADAM	O
,	O
supported	O
view	O
(	O
model	O
)	O
entry	O
,	O
view	O
merging	O
,	O
selective	O
(	O
subset	O
)	O
viewing	O
,	O
namespace	O
inheritance	O
,	O
normalization	O
,	O
a	O
quality	O
assurance	O
analysis	O
of	O
views	O
,	O
entity	B-Architecture
relationship	I-Architecture
graph	O
and	O
report	O
generation	O
,	O
transformation	O
to	O
a	O
relational	O
database	O
expressed	O
as	O
SQL	O
data	O
declaration	O
statements	O
,	O
and	O
referential	O
integrity	O
checking	O
SQL	O
.	O
</s>
<s>
Logical	O
models	O
were	O
serialized	O
with	O
a	O
structural	O
modeling	B-Language
language	I-Language
.	O
</s>
<s>
The	O
graphic	O
syntax	O
of	O
LDDT	O
differed	O
from	O
that	O
of	O
IDEF1	B-Application
and	O
,	O
more	O
importantly	O
,	O
LDDT	O
contained	O
many	O
interrelated	O
modeling	O
concepts	O
not	O
present	O
in	O
IDEF1	B-Application
.	O
</s>
<s>
Therefore	O
,	O
instead	O
of	O
extending	O
IDEF1	B-Application
,	O
Mary	O
E	O
.	O
Loomis	O
of	O
DACOM	O
wrote	O
a	O
concise	O
summary	O
of	O
the	O
syntax	O
and	O
semantics	B-Application
of	O
a	O
substantial	O
subset	O
of	O
LDDT	O
,	O
using	O
terminology	O
compatible	O
with	O
IDEF1	B-Application
wherever	O
possible	O
.	O
</s>
<s>
DACOM	O
labeled	O
the	O
result	O
IDEF1X	B-Application
and	O
supplied	O
it	O
to	O
the	O
ICAM	O
program	O
,	O
which	O
published	O
it	O
in	O
1985	O
.	O
</s>
<s>
Connection	O
relationships	O
A	O
relationship	O
having	O
no	O
semantics	B-Application
in	O
addition	O
to	O
association	O
.	O
</s>
<s>
View	O
levels	O
Three	O
levels	O
of	O
view	O
are	O
defined	O
in	O
IDEF1X	B-Application
:	O
entity	B-Architecture
relationship	I-Architecture
(	O
ER	O
)	O
,	O
key-based	O
(	O
KB	O
)	O
,	O
and	O
fully	O
attributed	O
(	O
FA	O
)	O
.	O
</s>
<s>
The	O
three-schema	B-Application
approach	I-Application
in	O
software	B-General_Concept
engineering	I-General_Concept
is	O
an	O
approach	O
to	O
building	O
information	O
systems	O
and	O
systems	O
information	O
management	O
,	O
that	O
promotes	O
the	O
conceptual	B-Application
model	I-Application
as	O
the	O
key	O
to	O
achieving	O
data	B-General_Concept
integration	I-General_Concept
.	O
</s>
<s>
A	O
schema	O
is	O
a	O
model	O
,	O
usually	O
depicted	O
by	O
a	O
diagram	O
and	O
sometimes	O
accompanied	O
by	O
a	O
language	B-Language
description	O
.	O
</s>
<s>
At	O
the	O
center	O
,	O
the	O
conceptual	B-Application
schema	I-Application
defines	O
the	O
ontology	B-Language
of	O
the	O
concepts	O
as	O
the	O
users	O
think	O
of	O
them	O
and	O
talk	O
about	O
them	O
.	O
</s>
<s>
The	O
physical	O
schema	O
describes	O
the	O
internal	O
formats	O
of	O
the	O
data	O
stored	O
in	O
the	O
database	O
,	O
and	O
the	O
external	O
schema	O
defines	O
the	O
view	O
of	O
the	O
data	O
presented	O
to	O
the	O
application	B-Application
programs	I-Application
.	O
</s>
<s>
Like	O
any	O
model	O
,	O
it	O
is	O
used	O
to	O
represent	O
and	O
reason	O
about	O
the	O
subject	O
of	O
the	O
model	O
-	O
in	O
this	O
case	O
IDEF1X	B-Application
.	O
</s>
<s>
The	O
meta	O
model	O
is	O
used	O
to	O
reason	O
about	O
IDEF1X	B-Application
,	O
i.e.	O
,	O
what	O
the	O
constructs	O
of	O
IDEF1X	B-Application
are	O
and	O
how	O
they	O
relate	O
to	O
one	O
another	O
.	O
</s>
<s>
The	O
model	O
shown	O
is	O
an	O
IDEF1X	B-Application
model	O
of	O
IDEF1X	B-Application
.	O
</s>
<s>
Such	O
meta	O
models	O
can	O
be	O
used	O
for	O
various	O
purposes	O
,	O
such	O
as	O
repository	O
design	O
,	O
tool	O
design	O
,	O
or	O
in	O
order	O
to	O
specify	O
the	O
set	O
of	O
valid	O
IDEF1X	B-Application
models	O
.	O
</s>
<s>
First	O
,	O
they	O
specify	O
syntax	O
but	O
not	O
semantics	B-Application
.	O
</s>
<s>
Second	O
,	O
a	O
meta	O
model	O
must	O
be	O
supplemented	O
with	O
constraints	O
in	O
natural	O
or	O
formal	O
language	B-Language
.	O
</s>
<s>
The	O
formal	O
theory	O
of	O
IDEF1X	B-Application
provides	O
both	O
the	O
semantics	B-Application
and	O
a	O
means	O
to	O
precisely	O
express	O
the	O
necessary	O
constraints	O
.	O
</s>
<s>
A	O
meta	O
model	O
for	O
IDEF1X	B-Application
is	O
given	O
in	O
the	O
adjacent	O
figure	O
.	O
</s>
<s>
The	O
meta	O
model	O
informally	O
defines	O
the	O
set	O
of	O
valid	O
IDEF1X	B-Application
models	O
in	O
the	O
usual	O
way	O
,	O
as	O
the	O
sample	O
instance	O
tables	O
that	O
correspond	O
to	O
a	O
valid	O
IDEF1X	B-Application
model	O
.	O
</s>
<s>
The	O
meta	O
model	O
also	O
formally	O
defines	O
the	O
set	O
of	O
valid	O
IDEF1X	B-Application
models	O
in	O
the	O
following	O
way	O
.	O
</s>
<s>
The	O
meta	O
model	O
,	O
as	O
an	O
IDEF1X	B-Application
model	O
,	O
has	O
a	O
corresponding	O
formal	O
theory	O
.	O
</s>
<s>
The	O
semantics	B-Application
of	O
the	O
theory	O
are	O
defined	O
in	O
the	O
standard	O
way	O
.	O
</s>
<s>
Every	O
model	O
for	O
the	O
IDEF1X	B-Application
theory	O
corresponding	O
to	O
the	O
IDEF1X	B-Application
meta	O
model	O
and	O
its	O
constraints	O
is	O
a	O
valid	O
IDEF1X	B-Application
model	O
.	O
</s>
