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relation to signify that one data type in a service domain directly
implements one data type in a business domain. For example, in
Figure 3.1, data type
order
in the service domain is the realization
of data type
ORDER
in the business one. In the following sections of
this chapter, a pair of data types, one's name in the lower case and the
other's in the upper case, has the realization relation between them.
Given that the granularity of business data is usually coarser than
that of service data, a complete realization relation between them is not
guaranteed. To model an incomplete realization relation between them,
we use two stereotypes to extend the realization relation:
partial
and
specialized
realizations.
1. Partial realization describes the situation that service data realize
a part of business data. For example, in Figure 3.1, data type
inhouse_ws
is a part of
worksheet
, which realizes
WORKSHEET
.
Thus, we define
inhouse_ws
as the
partial realization
of
WORKSHEET
.
2. Specialized realization describes the situation that service data
realize a special kind of business data. For example, in Fig-
ure 3.1, data type
nl_order
is a special class of data type
order
,
which realizes
ORDER
. Thus, we define
nl_order
as the
specialized realizatio
nof
ORDER
.
Figure 3.1 illustrates all the data relations we have discussed and gives
the notations to model these relations. For simplicity, we only present the
UML model while the actual data definition in XML is omitted.
3.1.2 Problem Formulation
In Section 3.1.1, we use UML notation to express data relations. To save
some space, we show only the graph presentation of UML class
diagrams, and in this subsection, we show their corresponding Petri
net constructs.
To align with the requirement of process composition, we use
colored Petri nets to represent all the data relations in a service domain,
as illustrated in Figure 3.2. In Figure 3.2, the notation of a place (e.g.,
order
) represents the color set attached to it. The color set in turn
represents a data type associated with this place. A hollow transition
represents the generation relation between two data types (
order
can
