Pattern-Based Modeling and Formalizing of Business Process Quality Constraints - Advanced Information Systems Engineering - page 523

Anonymous steps: A quality constraint may refer to an anonymous step which could
be an unknown action or an unknown guard. For example, a quality constraint might be
dedicated to ensure that the business process model in Fig. 1 includes a possibility to
accept the application after 6 steps from starting the process without any need to know
to which actions or guards these steps are referring. Quality constraints which counts
anonymous steps are useful if the number of steps refers e.g. to the time consumed or the
money paid to perform these steps, or if it plays a role in the satisfaction of the customer.
For this reason, we introduce in EPPSL a modeling element called "AnonymousStep"
(Fig. 2.e).

Partial quality constraints: A partial quality constraint is a quality constraint which is
linked to other partial quality constraint(s) with a logical relationship to build another
quality constraint. We use the concept of the partial quality constraint, since we need
sometimes to model a quality constraint which consists of several quality constraints
that are logically related, but temporally not related. For example, a quality constraint
might be dedicated to ensure that if the business process model in Fig. 1 includes a
possibility to make an interview, then it includes no possibility to accept the application
online. The first possibility is not temporally related to the second one. However, they
are logically related, since the first possibility implies the negation of the second one.
We model partial quality constraints as separated units. For this reason, we provide in
EPPSL a modeling element called "ConstraintContainer" (Fig. 2.f) which is dedicated
to contain a partial quality constraint model separating it temporally from other partial
quality constraint models.
The elements in Fig. 2.a, Fig. 2.b, Fig. 2.c, and Fig. 2.d are the same elements used
by UML 2.0 Activity Diagrams to model Actions, InitialNodes, ActivityFinalNodes,
and Guards. The elements in Fig. 2.e and Fig. 2.f are new classes defined by EPPSL.

Fig. 2. EPPSL modeling elements for the basic blocks

EPPSL models for quality constraints provide the ability to link the modeling ele-
ments of the basic blocks with temporal and logical relationships. In the following, we
introduce how EPPSL can model these relationships.

4.2 Modeling Temporal Relationships

A temporal relationship determines the order of actions, guards, and anonymous steps.
For example, QC 2 , which we want to verify on the business process model in Fig. 1,
consists of a temporal relationship "After":