Single hoist cyclic scheduling with multiple tanks: a material handling solution

A hoist controlled by a computer is widely used for moving electroplates which is chemically treated in a sequence of tanks. The hoist scheduling directly affects the throughput of a production system. The objective of the hoist scheduling problem is to schedule the moves to maximize the throughput. This paper investigates the hoist scheduling problem, a specific material handling issue, in a manufacturing environment. The scope of the study is in the area of single hoist cyclic scheduling with multiple tanks. The purpose of the study is to develop a mixed integer linear programming model that can be used to schedule multiple tanks and improve throughput in a process industry. Specifically, a method has been proposed to estimate the processing time in a bottleneck stage with multiple tanks.