There are two ways to tell if the timing belt has been replaced. One is obvious-you are looking at a service receipt showing the replacement.
Swimlane diagrams are used whenever you need to show activities, tasks, or process steps which are being performed by different actors/roles. You can use swimlanes to group activities in an activity diagram or process flow by any category what you need: by role, by system, by department, etc.
In the Shapes window, in the Cross-Functional Flowchart Shapes stencil, drag a Swimlane shape (either horizontal or vertical) onto an empty area of the diagram. Each new swimlane comes with a label bar, which says Function by default; to change the label, double-click the bar.