A system for attendance pre-assignment. The system may include a memory storing instructions and at least processor configured to execute the instructions to perform operations. The operations may include retrieving, from a database, a plurality of delivery routes and a plurality of delivery sub-routes, wherein the delivery sub-routes are part of the delivery routes; calculating, based on the retrieval, a number of packages allocated to the delivery routes and the delivery sub-routes; receive data comprising groups of pre-assigned workers available for deliveries, the workers being classified into a plurality of categories; comparing, based on the received groups, the pre-assigned workers against the delivery routes and the delivery sub-routes; assigning, based on the comparison, the packages, the delivery routes, and the delivery sub-routes to the pre-assigned workers; generating a plurality of candidate routes associated with the pre-assigned workers; and calibrating, based on the assignment and the generated candidate routes, the delivery sub-routes.