Dynamic Vehicle Routing Problems with Pickup and Delivery Time Windows - Territory Planning and Scheduling

Pickup and delivery operations occur in transportation services of commodities and people. This study considers scheduling regular customers and real-time customers using multiple delivery resources. Each customer requests for a pickup service at the customer site, followed by a delivery service at the depot. Schedule consistency is considered for regular customers through imposed time window constraints and response time performance is emphasized for real-time customers. Applications include courier service and transportation of handicapped and elderly to hospitals.The methodology is divided into three phases: developing initial routes, service territory planning and dynamic scheduling. Initial routes are first developed for regular customers whose information is available. Service territories are adjusted due to workload fluctuations in recent periods in order to maintain a satisfactory level of response time or/and to balance workload among territories. Dynamic scheduling algorithms are developed to service all customers satisfying the time window constraints with the objective of minimizing total cost of resources. Coordinated strategies among resources, not much studied in dynamic scheduling problems with time windows, are adapted from the static problem to the dynamic problem. Results will be compared with the independent operating strategy commonly adopted in literature.