Stochastic Coloured Petri Nets for Modelling and Performance Evaluation of Automated Storage and Retrieval Systems

This paper presents stochastic coloured petri nets based approach for modelling and performance evaluation of automated storage and retrieval systems having single stacker crane with on-board storage. Effects of crane operation modes and assignment policies on the performance of automated storage and retrieval system have been analyzed with a hypothetical case study. The stacker crane is equipped with on-board storage for multiple unit load handling. The influence of variation in the on-board storage capacity on average service time of the crane, and on average waiting time and average queue length of retrieval and storage requests has been observed for different assignment policies and crane operation modes. A software package SCOLPEN has been used for the purposes of simulation and performance evaluation of the modelled system.