Supplementary Services Provided by Dial-a-Ride Systems

This study examines the completion of so-called supplementary services in a dial-a-ride system. The study focuses on health care and its related services because most Western countries have problems recruiting care workers. Therefore, a new problem definition is presented where service requests of the home health care routing and scheduling problem are integrated into a dial-a-ride problem setup. This represents a major change in the decision-making process of the dial-a-ride problems as serving additional requests negates the assumption that all requests made address only a transportation need. However, no change in the conditions takes place, i.e., the agreed conditions for the completion of dial-a-ride services are safeguarded. This means that a subset of health care services, which require low qualification and are addressed in a collaboration framework, may be completed by these drivers to unburden the care workers. Note that the collaboration is understood one way, i.e., the health care provider forwards the requested services to the dial-a-ride provider and not vice versa. There is no obligation for the dial-a-ride provider to accept all additional jobs. In order to gain further insights into the matter, a brief literature review of the relevant papers on the home health care routing and scheduling problem and the dial-a-ride problem is given. A formal problem description is provided and a bi-objective two-index mixed-integer program is presented. The program is embedded in an \(\varepsilon \) -constraint framework. Due to the limited capabilities of exact methods, a heuristic framework is presented. Results are reported for both the exact method and the heuristic algorithms using a selected test data set, and conclusions are drawn.