EPC - Event-driven Process Chain

EPC stands for Event-driven Process Chain. It is a semi-formal language used to model business processes. An EPC is viewed as an oriented graph composed of events and functions. EPC also has connectors to give a wider range of possibilities in the business process modelling, such as parallel execution or alternative paths to the execution flow.

There are three major elements in an EPC: events, functions and connectors.

Events are passive elements in EPC. They don’t describe tasks/activities to be made, only under what circumstances a function works, or in witch state a function will end. In the EPC graph an event is represented as hexagon. “Project accepted” or “Project refused” are examples of events.

Functions are active elements in EPC. They correspond to an activity (task, process step) which needs to be executed. Several resulting states may occur, where the modelling of this situation is helped by logical connectors. In the EPC graph a function is represented as rounded rectangle. “Make Proposition” or “Change Initial Proposition” are examples of functions.

Connectors can be used to connect functions and events. With them, the control flow can be specified. There are three types of connectors: AND, XOR (exclusive or) and OR.

In general, an EPC diagram must start and end with an event.

You can see an example here.