EPC Diagrams Overview

Event Process Chain modeling technique is available in the IDS/Scheer ARIS Toolset. Process chains describe the sequencing and interaction between data, process steps, IT systems, organizational structure and products. An EPC always starts and ends with events, which define the state or condition under which a process starts and the state under which it ends.
A function /activity is a technical task, a procedure, and/or an activity performed on an object to support one or more company goals (i.e. Manufacturing).

Figure 1: ARIS  symbols

Events act as triggers for activities, but are also based on preceding functions and therefore describe an event. EPC Diagrams follow an event-function (activity)-event structure, they must begin and end with events.

Figure 2: event-activity-event

Logical branches in the chronological flow of the process are represented by rules in the form of logical operators (AND, OR, XOR). Branching is done with three types of connectors:

1. AND
2. OR
3. XOR (exclusive OR)

There are some rules about using each type of connector, you can find them in ARIS documentation. When you need to model the processes with additional information, you can assign organizational unit/role/person/location to activity, to illustrate who is performing an activity. A process generates data, or requires data to be able to continue, so you can use Database symbol for data flow in the process. Some activities are performed in external IT systems (i.e. CRM), so drag&drop IT system symbol and associate it with such activity. If there is activies with critical effects on process, assign the Risk symbol to them, so you can define countermeasures.

Figure 3: additional symbols in EPC

EPCs are typically used at the lower levels of the process hierarchy. If technical and business processes need to be described, other methods, such as BPMN or UML are used instead of EPCs.