Similar to Flow objects or connections, Artifacts represent a group of BPMN 2.0 elements.
Their aim is to provide supporting information about a process diagram, or elements within a process diagram. BPMN artifacts are extendable, and currently BPMN 2.0 provides three standardized Artifacts: Associations, Groups, and Text Annotations.
A Text annotation represents a mechanism for a modeler to provide additional textual information for the reader of a BPMN diagram. They can float freely anywhere on the diagram, and are commonly related to an element of a BPMN diagram. It is important to stress that a Text annotation element does not affect the flow of the process in any way.
An association should be used when information and artifacts need to be associated with flow objects.
It is drawn with a dotted single line. If there is a reason to put directionality on the association, then an arrowhead may be added to the line. This can be in one direction or in both directions. These can also be used to show the activity used for compensation in a transactional sub-process.
A Group is a dashed, rounded rectangle used to surround a group of flow elements to highlight or to categorize them. In contrast to sub-processes, groups don’t add additional constraints on process performance, and commonly act as a container for reporting.
Since artifacts are extendable, process modelers and tool vendors can extend BPMN through the addition of new types of Artifacts, as long as these extensions do not impact the standardized behavior of a diagram. Examples of non-standardized BPMN artifacts, are: “Constraint”, “Requirement” and “Control”.Business Process Analysis BPMN Video