Along with the cost per storage location, throughput and storage capacity considerations are critical requirements in the planning and selection of a storage system. Cycle times and throughput are useful in the early conceptual, design, and planning phases of new storage systems, where different systems need to be compared based on these performance parameters. The approaches to determining the throughput and travel times of storage systems can be derived by modularly capturing and combining the basic functions of a storage system—handling a container, moving a container in three-dimensional space, and storing and retrieving a container—and the relationships between these functions. In addition to the deterministic time components for movement, the stochastic components resulting from the distribution of goods in the storage system and the waiting times at the transitions between the various basic functions must also be considered.

Over the past 60 years, new storage systems have been continuously developed by material handling equipment suppliers, for which the scientific community subsequently developed the corresponding analytical approaches to determine throughput. These were later implemented into easily accessible industry guidelines. A critical analysis reveals that scientific progress has been driven by technical developments, with the development of analytical models for existing systems following suit. One goal of this project is to demonstrate that it is possible to develop throughput models concurrently with or prior to the first technical implementations.

Objectives and Methodology

The working hypothesis of this research project is to find a method to map all currently existing storage systems from a valid morphological box, in order to derive all conceivable possible storage systems and configurations. Additionally, the generation of analytical models for all derived systems should be possible to calculate the given system parameters (throughput, cycle times, etc.) and to derive a new, quantifiable understanding of the relationships in storage systems. The modularity of the models and methods offers the possibility to derive new types of storage systems with corresponding approaches.

For this purpose, the creation of a morphological box and a method for the automatic derivation of throughput models will be researched. The validation of the determined throughput models and the automatic methods will be carried out using additionally created simulation models.