Weekly home health care logistics

Weekly home health care (HHC) logistics optimization problem is considered in this paper. It extends the classical Periodic Vehicle Routing Problem with Time Windows to three types of demands of patients at home. Demands include transportation of drugs/medical devices between the HHC depot and patients´ homes, delivery of special drugs from a hospital to patients, and delivery of blood samples from patients to a lab. The weekly demand of each patient is represented by a set of alternative visit patterns. Daily routing is subject to time window constraints of patients and precedence constraints of hospital and lab visits. The goal is to minimize the maximal routing costs among all routes of the week. Various combinations of tabu search and different local search schemes are used to solve the problem. Numerical results show that local search starting with an infeasible local search with a small probability followed by a feasible local search with high probability performs quite well.