<s>
A	O
metaCASE	B-Application
tool	I-Application
is	O
a	O
type	O
of	O
application	B-Application
software	I-Application
that	O
provides	O
the	O
possibility	O
to	O
create	O
one	O
or	O
more	O
modeling	O
methods	O
,	O
languages	O
or	O
notations	O
for	O
use	O
within	O
the	O
process	O
of	O
software	O
development	O
.	O
</s>
<s>
MetaCASE	B-Application
tools	I-Application
are	O
thus	O
a	O
kind	O
of	O
language	O
workbench	O
,	O
generally	O
considered	O
as	O
being	O
focused	O
on	O
graphical	O
modeling	O
languages	O
.	O
</s>
<s>
Another	O
definition	O
:	O
MetaCASE	B-Application
tools	I-Application
are	O
software	O
tools	O
that	O
support	O
the	O
design	O
and	O
generation	O
of	O
CASE	O
tools	O
.	O
</s>
<s>
In	O
general	O
,	O
metaCASE	B-Application
tools	I-Application
should	O
provide	O
generic	O
CASE	O
tool	O
components	O
that	O
can	O
be	O
customised	O
and	O
instantiated	O
into	O
particular	O
CASE	O
tools	O
.	O
</s>
<s>
The	O
intent	O
of	O
metaCASE	B-Application
tools	I-Application
is	O
to	O
capture	O
the	O
specification	O
of	O
the	O
required	O
CASE	O
tool	O
and	O
then	O
generate	O
the	O
tool	O
from	O
the	O
specification	O
.	O
</s>
<s>
Building	O
large-scale	O
software	B-Application
applications	I-Application
is	O
very	O
complicated	O
process	O
which	O
is	O
not	O
easy	O
to	O
handle	O
.	O
</s>
<s>
MetaCASE	B-Application
products	O
are	O
usually	O
highly	O
specialised	O
,	O
application	O
development	O
environments	O
which	O
produce	O
a	O
custom	O
tool(set )	O
from	O
a	O
high	O
level	O
description	O
of	O
the	O
required	O
tools	O
.	O
</s>
<s>
So	O
in	O
other	O
words	O
metaCASE	B-Application
technology	O
approaches	O
the	O
methodology	O
automation	O
from	O
a	O
dynamic	O
perspective	O
.	O
</s>
<s>
MetaCASE	B-Application
tools	I-Application
allow	O
definition	O
and	O
construction	O
of	O
CASE	O
tools	O
that	O
support	O
arbitrary	O
methodologies	O
.	O
</s>
<s>
Most	O
CASE	O
tools	O
for	O
object-oriented	B-Application
modeling	I-Application
are	O
heavily	O
based	O
on	O
the	O
UML	B-Language
method	O
.	O
</s>
<s>
A	O
method	O
also	O
dictates	O
other	O
CASE	O
tool	O
functions	O
,	O
such	O
as	O
how	O
models	O
can	O
be	O
made	O
,	O
checked	O
and	O
analyzed	O
,	O
and	O
how	O
code	B-Application
can	O
be	O
generated	O
.	O
</s>
<s>
For	O
example	O
,	O
a	O
tool	O
can	O
generate	O
CORBA	B-Architecture
IDL	I-Architecture
definitions	O
only	O
if	O
the	O
modeling	O
language	O
can	O
adequately	O
specify	O
and	O
analyze	O
CORBA	B-Architecture
compliant	O
interfaces	B-Application
.	O
</s>
<s>
the	O
tool	O
(	O
and	O
method	O
)	O
does	O
not	O
generate	O
them	O
,	O
it	O
offers	O
very	O
little	O
,	O
if	O
any	O
,	O
support	O
for	O
work	O
on	O
interface	B-Application
design	O
and	O
implementation	O
.	O
</s>
<s>
Typically	O
they	O
also	O
find	O
it	O
difficult	O
to	O
map	O
the	O
concepts	O
and	O
semantics	O
used	O
in	O
the	O
models	O
to	O
their	O
application	B-Architecture
domain	I-Architecture
.	O
</s>
<s>
After	O
creating	O
the	O
models	O
,	O
which	O
fail	O
even	O
to	O
illustrate	O
the	O
application	B-Architecture
domain	I-Architecture
adequately	O
,	O
the	O
tool	O
does	O
not	O
provide	O
the	O
necessary	O
reports	O
nor	O
does	O
it	O
generate	O
the	O
required	O
code	B-Application
.	O
</s>
<s>
Later	O
when	O
the	O
situation	O
in	O
the	O
application	B-Architecture
domain	I-Architecture
evolves	O
and	O
the	O
development	O
environment	O
changes	O
you	O
may	O
incrementally	O
update	O
the	O
method	O
support	O
in	O
your	O
CASE	O
tool	O
.	O
</s>
<s>
This	O
is	O
exactly	O
what	O
metaCASE	B-Application
technology	O
offers	O
.	O
</s>
<s>
Traditional	O
CASE	O
tools	O
are	O
based	O
on	O
a	O
two-level	O
architecture	O
:	O
system	O
designs	O
are	O
stored	O
into	O
a	O
repository	B-Application
,	O
whose	O
schema	B-Application
is	O
programmed	B-General_Concept
and	O
compiled	B-Language
into	O
the	O
CASE	O
tool	O
.	O
</s>
<s>
Most	O
importantly	O
,	O
only	O
the	O
tool	O
vendor	O
can	O
modify	O
the	O
method	O
,	O
because	O
it	O
is	O
fixed	O
in	O
the	O
code	B-Application
.	O
</s>
<s>
MetaCASE	B-Application
technology	O
removes	O
this	O
limitation	O
by	O
providing	O
flexible	O
methods	O
.	O
</s>
<s>
MetaCASE	B-Application
tools	I-Application
are	O
based	O
on	O
a	O
three-level	O
architecture	O
:	O
</s>
<s>
However	O
,	O
instead	O
of	O
being	O
embedded	O
in	O
code	B-Application
in	O
the	O
tool	O
,	O
as	O
in	O
a	O
fixed	O
CASE	O
tool	O
,	O
the	O
method	O
is	O
stored	O
as	O
data	O
in	O
the	O
repository	B-Application
.	O
</s>
<s>
Many	O
method	O
books	O
now	O
include	O
metamodels	O
of	O
their	O
method	O
,	O
and	O
several	O
important	O
innovations	O
,	O
such	O
as	O
XMI	B-Language
,	O
are	O
metamodel-based	O
.	O
</s>
<s>
Unlike	O
a	O
CASE	O
tool	O
,	O
a	O
metaCASE	B-Application
tool	I-Application
allows	O
the	O
user	O
to	O
modify	O
the	O
metamodel	O
.	O
</s>
<s>
Hence	O
,	O
metaCASE	B-Application
is	O
based	O
on	O
the	O
flexibility	O
of	O
the	O
method	O
specifications	O
.	O
</s>
<s>
This	O
level	O
is	O
the	O
hard-coded	O
part	O
of	O
the	O
metaCASE	B-Application
software	O
.	O
</s>
<s>
This	O
dependency	O
structure	O
is	O
similar	O
to	O
that	O
between	O
objects	O
,	O
classes	O
and	O
metaclasses	O
in	O
some	O
object-oriented	B-Language
programming	I-Language
languages	I-Language
.	O
</s>
<s>
Jackson	O
recognises	O
the	O
vital	O
difference	O
between	O
an	O
application	O
’s	O
domain	O
and	O
its	O
code	B-Application
:	O
two	O
different	O
worlds	O
,	O
each	O
with	O
its	O
own	O
language	O
,	O
experts	O
,	O
ways	O
of	O
thinking	O
etc	O
.	O
</s>
<s>
The	O
difficult	O
job	O
of	O
the	O
software	B-General_Concept
engineer	I-General_Concept
is	O
to	O
build	O
a	O
bridge	O
between	O
these	O
worlds	O
,	O
at	O
the	O
same	O
time	O
as	O
solving	O
problems	O
in	O
both	O
worlds	O
.	O
</s>
<s>
In	O
a	O
metaCASE	B-Application
tool	I-Application
,	O
there	O
is	O
complete	O
freedom	O
to	O
change	O
the	O
method	O
,	O
or	O
even	O
develop	O
an	O
entirely	O
new	O
method	O
.	O
</s>
<s>
Both	O
models	O
and	O
metamodels	O
(	O
method	O
descriptions	O
)	O
are	O
stored	O
as	O
first-class	O
elements	O
in	O
the	O
repository	B-Application
.	O
</s>
<s>
Research	O
prototypes	O
and	O
even	O
commercial	O
metaCASE	B-Application
tools	I-Application
have	O
existed	O
for	O
many	O
years	O
,	O
but	O
only	O
recently	O
have	O
there	O
been	O
tools	O
which	O
are	O
mature	O
,	O
user-friendly	O
and	O
stable	O
for	O
both	O
the	O
method	O
developer	O
and	O
the	O
method	O
user	O
.	O
</s>
<s>
One	O
of	O
the	O
most	O
widely	O
known	O
and	O
used	O
metaCASE	B-Application
tools	I-Application
is	O
MetaEdit+	B-Application
.	O
</s>
