"A swim lane (or swimlane) is a visual element used in process flow diagrams, or flowcharts, that visually distinguishes responsibilities for sub-processes of a business process. Swim lanes may be arranged either horizontally or vertically. In the accompanying example, the swimlanes are named Customer, Sales, Contracts, Legal, and Fulfillment, and are arranged vertically. ...
When used to diagram a business process that involves more than one department, swimlanes often serve to clarify not only the steps and who is responsible for each one, but also how delays, mistakes or cheating are most likely to occur.
Many process modeling methodologies utilize the concept of swimlanes, as a mechanism to organize activities into separate visual categories in order to illustrate different functional capabilities or responsibilities (organisational roles). Swimlanes are used in Business Process Modeling Notation (BPMN) and Unified Modeling Language activity diagram modeling methodologies." [Swim lane. Wikipedia]
The template "UML activity diagram (swimlanes)" for the ConceptDraw PRO diagramming and vector drawing software is included in the Rapid UML solution from the Software Development area of ConceptDraw Solution Park.