Information Technology Reference
In-Depth Information
A
C
Requirement
Business
domain
Service
domain
Service portfolio
Refined
process
a
b
a
b
c
c
b
Figure 3.4
Sequential composition rule.
3.2.1 Sequential Composition Rule
The sequential composition rule is illustrated in Figure 3.4. For a
business requirement
A
!
C
, if there are two operations in service
portfolio,
a
c
, we can refine the business requirement into
a process realized by existing services, that is,
a
!
b
and
b
!
!
b
!
c
.
3.2.2 Parallel Composition Rule
We explain this rule through an example in Figure 3.5. If
a
¼
a
1
a
2
,
b
¼
b
1
b
2
, and we have two operations
f
a
1
!
b
1
;
a
2
!
b
2
g
,
the
requirement
A
!
B
can be realized by the AND collection of
f
a
1
!
b
1
;
a
2
!
b
2
g
, with two additional mediation transitions as
Data relation
Requirement
A
B
B
A
Business
domain
Service
domain
a
1
Refined
process
a
b
a
2
a
b
1
b
2
1
b
a
b
1
a
b
2
2
Service portfolio
Figure 3.5
Parallel composition rule.
