EPC

EPC notation (Event-Driven Process Chain) is used to model lower-level processes. An Event-driven process chain is an ordered graph of events and functions. Each function can identify initial and end events, participants, actors, material objects and documents accompanying it. EPC functions can be decomposed in either EPC or BPMN notation to be described on a more detailed level. When you decompose an EPC activity placed on a SADT diagram, no arrows are migrated from the SADT diagram to the EPC diagram.

See Table 1 for the description of the EPC notation elements.

Element	Button	Shape	Description
Function			A function is a task or activity performed over an object (document, material object, etc.) in order to produce a given result. The order of function shapes defines the flow of process steps.
Event			An Event describes a state that controls or influences progression of the process. They trigger functions and are the results of functions.
Relationship			A relationship is a connection between two diagram shapes.
Operators			Operators are used to split and join the control flow. Split operators have one incoming and several outgoing connections. Join operators have several incoming connections and one outgoing connection.
Process Interface			An external process or function defines: - the process that is activated after the current process is performed, or the process that activates performance of the current process; - the process that delivers or receives an object.
Org Units			An org unit (Position, Department, Role or External org unit) performs a function, is its owner or participates in its performance.
Paper Document			A paper document is an input or an output of a function.
Electronic Document			An electronic document is an input or an output of a function.
Material Object			A material object is an input or an output of a function.
Information			Information flows are inputs or outputs of a function.
Application			An application performs a function or supports its performance.
Application Module			An application module performs a function or supports its performance.
Application Function			An application function performs a function or supports its performance.
Database			A database performs a function or supports its performance.
Term			A term is an input or an output of a function. It is usually used to represent a special abbreviation or a term specific for a company. Term may be used to set a status for an object from the Functional objects repository.
Object Group			A group of objects is an input or an output of a function, for example, "Project documentation".
Another Functional Object			An object that cannot be related to any specified class of functional objects. It is an input or an output of a function.

Table 1. EPC Notation Elements

When you decompose an EPC function that is placed on an EPC diagram, it is often necessary to move all the shapes associated with the function, to the decomposition diagram. When you first open the decomposition diagram, the "Copy shapes related to the decomposed function?" message appears. Click Yes, if you want to display all the shapes on the decomposition diagram.

Also, you can use the button on the Toolbar of the Diagram Window in case you decide to display these shapes some time later.

To link two shapes on a diagram, add a relationship and select its type (Figure 1). The relationship type is selected automatically if only one option is available. The relationship type can be changed in the Properties Window of the relationship.

Figure 1

Use the button to show / hide names of all the relationship types on a diagram.

The relationship type name will always be displayed in case the Relationship type name visibility property is selected for the relationship type in the Properties Window (Figure 2).

Figure 2. Manage visibility of the relationship type name on all EPC diagrams