Swim lane
A swim lane (or swimlane) is a visual element used in process flow diagrams that depict what or who is working on a particular subset of a process. Swim lanes are arranged either horizontally or vertically and are used for grouping the sub-processes according to the responsibilities of those swim lanes. In the accompanying example, the swimlanes are named Customer, Sales, Contracts, Legal, and Fulfillment.
Swim Lane flowchart
The swim lane flowchart differs from other flowcharts in that processes and decisions are grouped visually by placing them in lanes. Parallel lines divide the chart into lanes, with one lane for each person, group or subprocess. Lanes are labelled to show how the chart is organized.
In the accompanying example, the longitudinal direction represents the sequence of events in the overall process, while the lateral divisions depict what subprocess is performing that step. Arrows between the lanes represent how information or material is passed between the subprocesses.
Optionally, the flow can be rotated so that the sequence reads horizontally from left to right, with the roles involved being shown at the left edge. This can be easier to read and design, Microsoft Visio typically operates from left to right, as normally screen sizes are wider than they are deep which gives an improved view of the flow.
Use of standard symbols enable clear linkage to be shown between related flow charts when charting flows with complex relationships: use of hyperlinking capability makes movement between activities on different sheets easy and reliable.
It is typically but not exclusively used in manufacturing-related applications. It aims to help clarify the overall layout of the processes, for use in optimizing floor capacity and efficiency.
When used to diagram a business process that involves more than one department, it can clarify not only the steps and who is responsible for each one, but 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. Swimlanes are used in Business Process Modeling Notation (BPMN) and Unified Modeling Language Activity diagram modeling methodologies.

