What are “swimlanes” used for?
A swim lane (or swimlane diagram) is a visual element used in process flow diagrams, or flowcharts, that visually distinguishes job sharing and responsibilities for sub-processes of a business process.
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 labeled to show how the chart is organized.
In this example, you have a swimlane for Issues, another for Error correction, and another for New features.