Measure each part of the trip rather than the total alone
On two ordinary pickup days, record four times: when work or the earlier activity finished, when the collector could actually leave, when they reached the site, and when they reached the designated collection point. A person may arrive at the car park on time but need another six minutes to walk to the gate. Separate that from a late work finish; changing the alert solves only some of these problems.
Match the remedy to the observed cause
Choose the remedy that matches the evidence. Leaving earlier helps if the driver controls departure. If work ends after the latest possible departure, a louder reminder will not help. Change the collector, the preceding commitment, or the agreed pickup arrangement.
Check the next journey after making one change
If the second day shows that parking is the bottleneck, an earlier departure or a different authorized collection arrangement may help. Verify the actual access rules rather than guessing that another entrance can be used. If the previous commitment consistently ends too late, arrange a different collector or speak to the organizer about a workable time. Record the next actual arrival and compare it with the deadline. A change is useful when it fixes the gap repeatedly, not just on a quiet day.