Pull versus push strategy for automated guided vehicle load movement in a batch manufacturing system

Abstract

Most automated guided vehicle (AGV) dispatching rules reported in literature to date are based on the attributes of the vehicles and the workcenters from where the loads originate. These rules can therefore be described as source driven vehicle dispatching rules. In none of these rules is the load pickup priority determined based on the states of the load destinations. Therefore, the priority assignment algorithms used by source driven rules are inflexible for application in some manufacturing systems, especially those based on the just-in-time (JIT) principle. What is required for JIT manufacturing therefore is a demand driven rule. In this paper, an algorithm that assigns load movement priority based on the demand states of the load destinations is presented. When applied to the material flow of an illustrative shop, analysis indicates that the algorithm performs competitively with some of the best source driven rules currently reported. It also provides a material flow and workcenter priority assignment flexibility not matched by any source based rules.