Event-driven Process Chains:

Event-driven process chains are an important notation to model the domain
aspects of business processes. The main focus of this rather informal notation
is on representing domain concepts and processes rather than their formal
aspects or their technical realization. Event-driven process chains are part
of a holistic modelling approach, called the ARIS framework; ARIS stands
for Architecture of Integrated Information Systems, and it was developed by
August-Wilhelm Scheer.
This approach is often denoted as the ARIS house with three pillars and
a roof, as shown in Figure 4.32. The pillars reflect data, control and function,
while the roof reflects the overall organization. In each area, three levels of
abstraction are identified: a concept level, an architecture level, and an implementation
level, characterized by the terms Requirements Definition, Design
Specification, and Implementation Description, respectively.
The concept level is the highest level of abstraction in which data, control
and function are modelled. This level looks at nontechnical requirements of
business processes and their execution environment. Business goals and functions
are typical artefacts in the function view at this level.
The main views are as follows.
� Functional View: The functional view represents the goals and subgoals of
the enterprise and their relationships. In general, one subgoal might contribute
to a number of goals at the higher level. For instance, the subgoal
�reduce business process execution time� contributes to the goals �increase
customer satisfaction� and �reduce overall cost.�
At a lower level of abstraction, each subgoal is associated with a set of
functions that contribute to goals and subgoals. Functions are then hierarchically
decomposed until the desired granularity of functions is achieved,
similarly to functional decomposition in value chains.
� Organizational View: The organizational view describes the organizational
structure of an enterprise at a type level and at an instance level. There
are detailed specifications of organizational entities, including their relationships
and positions, roles, skills, and individuals associated with them.
Administration information such as the address of an organizational entity
can be represented. The organizational view also includes organizational
aspects of information technology of the enterprise, including its main
operational information systems, its storage facilities, and its network infrastructure.
� Data View: The data view characterizes business relevant data objects that
are manipulated by functions during business process execution. Entity
Relationship diagrams are used for data modelling.
� Business Value View or Output View: The business value view describes
the outcome of business processes, i.e., the products and services the enterprise
generates. These can be physical goods like automobiles or electronic
devices, as well as intangible goods, such as a processed order or a flight
booking.