Solution methods for the dynamic stochastic dial-a-ride problem with time-dependent travel speeds

Michael Schilde
2011 unpublished
The field of research regarding the optimization of humanitarian aid as well as health care efforts is very wide. During the last decades, the efforts expended in research projects related to this area are steadily increasing. In this book, we address a specific problem out of this large field: the transportation of elderly, ill and disabled persons. Such problems are commonly referred to as dial-a-ride problem (DARP) in the literature. We study three dynamic and stochastic variants of this
more » ... lem type with the aim of examining the effects of exploiting stochastic information about different future circumstances while planning. First, we consider stochastic information about future return transports and tailor two pairs of metaheuristic solution methods to the requirements of this problem. Second, we study the usage of stochastic information about future travel speeds while constructing the vehicle routes. Finally, we combine these two stochastic aspects with additional heterogeneous extensions regarding the vehicle fleet, the transported patients and multiple depots. Based on our findings we identify factors which have a strong influence on the potential benefits of exploiting stochastic information about future circumstances. Generally speaking, the benefits obtainable by planning in a stochastic way can be remarkable if the underlying conditions are suitable. Especially the total degree of dynamism present in a problem setting turns out to be negatively correlated with the achieved solution quality.
doi:10.25365/thesis.16073 fatcat:ajrudut57rhfflhxbk2dz3pwxi