By default, a start point will push work items through a simulation at the rate set by the user through a schedule or distribution. There may be situations however where you want a start point to provide a work item only when it is required by the system.

To do this you can change the settings on your start point so unlimited arrivals are selected. This can be found under the start point’s contextual menu / additional tab.

Once this has been selected, an arrival will be pulled in only when it is needed. For this to work the start point must be connected to a non-passive object, such as an activity. This could be a good setting to use whenever you assume there will always be a work item available when it is required.