Average Cycle Time Modelling for Multi-Aisles AS/RS Using Timed Petri Nets

Abstract

In this paper we consider the Multi-Aisle Automated Storage and Retrieval Systems where only one Storage/Retrieval machine (crane) is used, which has the advantage of decreasing the system costs but at the same time has the disadvantage of reducing the system throughput. This important performance evaluation parameter is highly related to another equally important one i.e. the cycle time of the crane. Because of its repercussions on the whole system performances, we are interested here in the modeling of this average cycle time, knowing that it could bring positive and significant advantages in terms of efficiency and accuracy, and consequently throughput and productivity. For that, the system to be studied is considered as Discrete Events System. To model it, we use a dedicated graphical tool known under the name Timed Petri Nets in the purpose to explore the theory used to evaluate the performances of these systems.