Information Technology Reference
In-Depth Information
A
business process
has at least one, but up to many outgoing
economic re-
source flows
. Similarly, a
business process
has at least one, but up to many
ingoing
economic resource flows
. In order to deliver a consistent
value chain
two important constraints on the business processes have to be considered: For
each
economic resource
in the
give
/
use
/
consume entity set
of the underly-
ing
duality
model, at least one corresponding incoming
economic resource flow
pointing to the same
economic resource
must exist. In analogy, for each
eco-
nomic resource
in the
take
/
produce entity set
of the underlying
duality
model,
at least one corresponding outgoing
economic resource flow
pointing to the same
economic resource
must exist. However, one may consider the substitutability
concept of more general and more specific economic resources as defined in a
resource generalization hierarchy. In other words, a duality model expecting an
economic resource in
give
/
use
/
consume entity set
may also accept a more
specific
economic resource
in the incoming
economic resource flow
.
In Figure 4(b) we depict an abstract example of a
value chain
to illustrate
its concepts and their stencils. Our
value chain
example includes four
business
processes
BP1, BP2, BP3, and BP4. The symbol for a
business process
is a
rounded rectangle.
Economic resource flows
are depicted by an arrow with the
economic resource
assigned to this arrow. For example, the
economic resource
R2
flows from BP1 to BP3. However, for esthetic reasons we provide an alternative
(but still similar) notation for
economic resource flows
that do not start from
or do not end in a
business process
. In this case, the arrow may start from the
economic resource
or may lead to the
economic resource
, instead of assigning the
economic resource
to the arrow. Examples are the resource flows of R1 leading
into BP1 and of R8 starting from BP4.
BP1 points to the
duality
model of Figure 3(b). In this
duality
model the
economic resource
R1 sits in the
give
partition; and the
economic resources
R2,
R3, R4, and R5 - where the latter is a
economic resources series
- are included in
the
take
partition. This is consistent with the
economic resource flows
to/from
BP1 in the
value chain
model of Figure 4(b). BP1 receives R1 and delivers
R2, R3, R4, and R5. It should be noted that the number of ingoing/outgoing
transitions does not necessarily meet the number of
economic resources
in the
duality
model, since a
business process
may provide an
economic resource
or -
more unlikely in practice - receive a resource from multiple business processes.
For example, BP2 provides R6 to both BP3 and BP4.
Let us assume that the
duality
model on which BP2 is based requires the
economic resources
R3, R5, and R7. In this case one might think of an incon-
sistency since BP2 receives R3 and R5, but R4 instead of R7. However, if R4
is defined as a specialization of R7 in a resource generalization hierarchy, the
model is consistent since in this case R4 may substitute R7 in the
duality
model
of BP2.
3.3 REA DSL Example
Having introduced the meta models and rather abstract examples, we now
demonstrate our REA DSL by means of a simple, but more realistic example.
