Pattern-Based Modeling and Formalizing of Business Process Quality Constraints - Advanced Information Systems Engineering - page 522

Fig. 1. Example of a business process model

4 Modeling Quality Constraints with EPPSL

We model a quality constraint by modeling its basic blocks and its temporal and logical
relationships. The basic blocks could be actions, guards, anonymous steps, and partial
quality constraints. The temporal and logical relationships are based on the semantics of
the temporal and logical relationships of CTL [6] to provide the ability to express both
deterministic and non-deterministic futures. In the following, we explain the semantics
of both basic blocks and relationships and how to model them.

4.1 Modeling Basic Blocks

A quality constraint may include a mixture of the following basic blocks:

Actions: An action is an activity which is carried out by the system, the customer or any
other entity in the business process. For example, QC 1 consists of the action "accept the
application". The start of a business process and the end of a control flow in a business
process are also considered to be actions. EPPSL uses the modeling elements "Action"
(Fig. 2.a), "InitialNode" (Fig. 2.b), and "ActivityFinalNode" (Fig. 2.c) to model actions,
the start of a business process, and the end of a control flow in a business process,
respectively.
Guards: A guard is a condition which can be false or true. For example, QC 1 consists
of the Guard "the number of required employees has not yet been reached". EPPSL uses
the modeling element "Guard" (Fig. 2.d) to model guards.