Part-Time Resources and Two-Hour Appointment Windows
A home-security company has 200 field resources. Forty are part-time and available only 08:00-12:00; 160 are full-time 08:00-17:00. Customers book two-hour arrival windows between 08:00 and 17:00. The implementation has one capacity area with the correct local time zone, one capacity category, and time slots defined for the full 08:00-17:00 day. Routing uses a daily routing plan and does not consider resource shifts when assigning time slots. As a result, 28% of appointments assigned to part-time technicians fall after 12:00; those technicians either work overtime or the appointment is reassigned. Overtime is up 14%, and customer wait time averages 3.1 hours because dispatchers manually move jobs. The company also wants part-time technicians to handle only jobs with estimated duration of 60 minutes or less. There are 1,800 activities per day and 12 work zones.
1. Why are part-time technicians receiving afternoon appointments, and what would you change in resource and capacity configuration?
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The capacity area and time slots cover 08:00-17:00 for every resource, so the routing engine sees afternoon capacity on part-time technicians even though their actual availability ends at 12:00. The resource shift or calendar is either missing or not being honored by routing. Define a part-time shift of 08:00-12:00 and a full-time shift of 08:00-17:00, assign the correct shift to each resource, and ensure the capacity area is in the correct local time zone. Do not model part-time availability only as a note or a skill; routing needs a time-based capacity constraint. Review the routing plan to confirm it considers resource work time and shifts when assigning time slots. If time-slot quotas are defined at the capacity-area level, ensure the afternoon slot capacity reflects only full-time resources, not all 200. Then test a part-time resource with an afternoon request: it should have no available capacity after 12:00 rather than receiving the job and triggering overtime.
2. How should the two-hour arrival windows be modeled to avoid overbooking while still using available capacity?
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Use time slots of two hours that match the customer promise, and set capacity per slot based on the number of resources actually available in that slot, adjusted for travel time and activity duration. Do not set one daily quota and assume it distributes evenly; that is how afternoon capacity gets promised on part-time resources. For each work zone and slot, calculate available technician-hours, subtract planned travel, and set the slot quota. The routing plan should assign activities to a slot and respect the slot capacity. If a slot is full, the booking interface should not offer it. Keep the service window on the activity so the technician and customer see the commitment, and make the time slot a routing constraint. Review slot utilization weekly; a slot that is consistently underused may be over-reserved, while a slot that consistently produces late arrivals may have travel time underestimated. Also account for the 12 work zones: a slot may have capacity in one zone and none in another.
3. Part-time technicians should handle only jobs estimated at 60 minutes or less. How would you enforce that in routing rather than in manual dispatch?
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Create a routing-visible distinction for short work and attach it to part-time resources. One option is a capacity category such as PT-Short, with a quota assigned only to part-time resources, and a routing plan or filter that sends activities with estimated duration of 60 minutes or less to that category. Another option is a work skill ShortJob assigned only to part-time technicians, with routing requiring that skill for short activities. Use the activity duration field as the filter criterion; do not rely on the activity type name alone, because duration varies. Keep full-time resources eligible for short jobs as overflow, but give the PT-Short category priority for those jobs so part-time capacity is used first. Test with a mix of 30-, 60-, and 90-minute activities: the 90-minute jobs must not land on part-time resources, and the 60-minute jobs should. Monitor violations and part-time utilization. If part-time technicians are idle while short jobs go to full-time resources, adjust the routing priority rather than adding manual dispatch.