Improving the efficiency of last-mile package deliveries using hybrid driver helpers

Abstract

An approach widely used by parcel delivery companies to deal with increased shipping volumes, especially during peak seasons, is the use of temporary workers called driver helpers. There are two types of driver helpers: (1) dependent helpers (DH) who work alongside drivers to deliver packages on daily routes, and (2) independent helpers (IDH) who do not travel with the drivers but rather work alone at their assigned locations. The standard practice is for each helper to be used as either a DH or an IDH, but not both. This article introduces the concepts of multitasking to the parcel delivery literature by proposing a new type of helper called the hybrid helper, which allows parcel carriers to utilize each helper as both a DH and an IDH in the same route. The hybrid-helper concept has several advantages over the existing DH or IDH concepts, including (1) reducing the transfer time of IDHs between locations, (2) allowing multiple delivery points to be serviced concurrently, and (3) increasing the daily work time of each helper. We develop a mathematical model that allows a vehicle to visit the same node more than once to enable IDH operations at selected nodes by a DH. Both numerical and field experiments show that our model outperforms other methods. Our results provide implications to practitioners on effective ways of utilizing helpers and suggest the need for future research to consider helpers in a broader context.