Network service scheduling and routing

Abstract

Real-life vehicle routing problems generally have both routing and scheduling aspects to consider. Although this fact is well acknowledged, few heuristic methods exist that address both these complicated aspects simultaneously. We present a graph theoretic heuristic to determine an efficient service route for a single service vehicle through a transportation network that requires a subset of its edges to be serviced, each a specified ( potentially different) number of times. The times at which each of these edges are to be serviced should additionally be as evenly spaced over the scheduling time window as possible, thus introducing a scheduling consideration to the problem. Our heuristic is based on the tabu search method, used in conjunction with various well-known graph theoretic algorithms, such as those of Floyd (for determining shortest routes) and Frederickson (for solving the rural postman problem). This heuristic forms the backbone of a decision support system that prompts the user for certain parameters from the physical situation (such as the service frequencies and travel times for each network link as well as bounds in terms of acceptability of results) after which a service routing schedule is suggested as output. The decision support system is applied to a special case study, where a service routing schedule is sought for the South African national railway system by SPOORNET (the semi-privatised South African national railways authority and service provider) as part of their rationalisation effort, in order to remain a lucrative company.

Network efficiency and vulnerability analysis using the flow‐weighted efficiency measure

“…Train delays due to various disturbances in rail‐bound transportation systems seem to be very likely and daily events (Groves et al., ). However, several special events such as train accidents, terroristic attacks, suicides, or closed stations are causing huge losses for the service providers (Miwa et al, ).…”

The Research of Terminal Distribution Network Path Optimization

“…A. Eliselt [7] mainly explores several categories such as: Chinese postman algorithm to the Chinese postal problems, have no to China post road, windy China postal problems, mixed China post road, heuristic China postal problems. G. Groves [8] study the profit maximization of China post road. W. L. Pharn [9] in combination with a variety of graph theory algorithm, at the same time considering the vehicle routing and scheduling management two aspects of the path optimization problem.…”