Online multi-server dial-a-ride problems

Abstract

Abstract. In an online dial-a-ride problem, a crew of servers has to process transportation requests as they arrive in real time. Possible ob-jective functions include minimizing the makespan and minimizing the sum of completion times. We give competitive algorithms and negative results for several online dial-a-ride problems with multiple servers. Sur-prisingly, in some cases the competitive ratio is dramatically better than that of the corresponding single server problem.