BPMN-Symbols

Activities

Activity

An activity describes a task that has to be completed in a process and is always assigned to a lane. An activity with several disciplines can be assigned to several lanes. The task is described from the perspective of the process participant who performs an activity, that is, the activity is described with an object and a verb.

Significance

  • BPMN element to describe an activity step-by-step
  • Always part of a lane
  • Use the BPMN-expansion “add participant” to an activity with more than one person


Language regulation

  • Mostly described in the view of the process participant that executes the activity. This means, the activity is described with an object and a verb.
  • The connector between two or more activities is called sequence flow.

Sub-Process

A sub-process is an activity consisting of several parts within a process or choreography. Because it consists of several parts, it can be further subdivided by sub-activities (a process or a choreography).

 

More complex activities and reusable steps are modelled as a sub-process.

 

  • Sub-process (opened) - the boundaries of the sub-process are expanded and the details (a process) are visible within the boundaries Note that sequence flows cannot exceed the boundaries of a sub-process.
  • Sub-process (closed) - the details of the sub-process are not visible on the map. A "plus" sign in the middle of the bottom frame indicates that the activity is a sub-process and that it is less detailed. 

Loop

A repetition (loop) is a feedback process which is described in the process map. Generally represented as a sequence flow, it implies a process within the feedback loop. Each repetition should be called a process. 

Gateways (G_)

A gateway represents a decision point and allows the process flow to be controlled, branched and merged.

Each gateway should be named according to its function within the process map (no special naming conventions are used for this purpose).

XOR - exclusive Gateway

  • Restrict the possible results to one path
  • either/or 

AND - parallel Gateway

  • Parallel process flow
  • All AND gateways wait until all incoming sequences are completed. 

OR - inclusive Gateway

  • One or more conditions are possible

Events (E_)

  • Events indicate that something is happening.
  • They always indicate the beginning and the end of a process as well as interactions within the process environment.

Start Event

  • Every process begins with a start (trigger).
  • There can only be one start event in a process. 

End Event

  • Each process is concluded with an end
  • An end result can symbolize not only successful ends but also failure.
  • In one process multiple final events are possible.

Intermediate Event

  • The event shows where something happens between the start and the ending of a process.
  • Intermediate events can "receive" or "send" triggers.

Message Events (E_)

  • Events indicate that something is happening.
  • They always indicate the beginning and the end of a process as well as interactions within the process environment.
  • A message event indicates whether a message for the task is sending or receiving.

Receiving Message

Message event

  • Incoming intermediate events are filled in white.

Sending Message

Message event

  • Outgoing intermediate events are filled in black.

Inpout / Output: Off-page connectors (E_)

  • A data input is an external input for the whole process, which is read by an activity and the externally visible input process interface.
  • A data output is a variable, which is generated as result of a whole process and the outwardly visible output process interface.

Data Input

  • Basic information, which comes from external disciplines. 
  • These disciplines usually occur only once and do not have their own swimming lanes

Data Output

  • Results, which are assigned to external disciplines (without own swimmlanes). 
  • This information is not needed later in the process anymore

Connectors

Sequence Flow

Defines the sequence of execution and must not exceed the limit of a pool. 

Conditional Flow

Contains a condition whether the path is executed or not.

Standard Flow

Is run through if all other conditions are not met. 

Message Flow

Represents the flow of messages between participants (pools), not to be used within a pool.

Data Objects

  • Data objects defined which information an activity requires and/or produces for it's execution. They cannot specify statuses and may not be the source or target of sequence or message flows. 
  • Data objects may be directly associated with a sequence flow connection. 
  • Data object elements must be located within a process or sub-process element.
  • Additional data object elements are data storages and messages

Data Object (DO_)

Data objects are non-model-based information, such as additional documents, data sheets, standards.

Data Store

Storage where process data can be written or read. Exists independently of the lifetime of the process instance.

Message

Indicates the content of a communication between two participants.

Data Object & Exchange Requirement

  • Within the data objects, the information exchange requirement is represented as a specific data object element

Data Object (DO_)

Data objects which do not represent an information exchange request uniquely identifiable (ID) and are designated with the prefix DO_.
They must have a name that indicates their purpose and a description that outlines their purpose and content. This usually involves non-model-based information, such as additional specifications, documents, leaflets, standards. 

Data Store

Information exchange requirements are uniquely identifiable (ID) and are designated by the prefix ER_
Each ER_ contains a name that uniquely reflects its purpose and a list of the actors (disciplines) necessary to fulfill the information exchange requirement 

Artifacts

IT-Systems

IT-Systems are connected by association between tasks.

Usually it is a system or a software application that is used in the course of the activity. 

Text Annotation

Each object can be commented.

Group

Several objects that are logically connected can be combined.