This paper studies the performance of static and real-time scheduling approaches in vehicle-based internal transport (VBIT) systems, which can be found in manufacturing and warehouse facilities. We propose three heuristic approaches for static VBIT problems (insertion, combined and column...

In this paper, we consider a newly-designed compact three-dimensional automated storage and retrieval system (AS/RS). The system consists of an automated crane taking care of movements in the horizontal and vertical direction. A gravity conveying mechanism takes care of the depth movement. Our...

Compact, multi-deep (3D) automated storage and retrieval systems (AS/RS) are becoming increasingly popular for storing products with relatively low turnover on a compact area. An automated storage/retrieval crane takes care of movements in the horizontal and vertical direction in the rack, and a...

Japanese companies value service and quality highly and they put much effort in realising this. However, survey research carried out in 2001 among senior managers of Japanese logistics companies in the Netherlands, indicated that these efforts do not result in significant performance differences...

Puzzle-based storage systems (PBSs) can achieve very high utilization of expensive and scarce storage space coupled with fully automated storage and retrieval of unit loads. A PBS system with one empty cell is comparable to the well-known 15-puzzle, in which 15 tiles slide in a 4×4 grid. This...

A Robotic Mobile Fulfillment System is a recently developed automated, parts-to-picker material handling system. Robots can move storage shelves, also known as inventory pods, between the storage area and the workstations and can continually reposition them during operations. This paper shows...

Warehouse operations are rapidly becoming more robotized to increase performance and cut costs. One important new way of working is in collaboration between humans and robots. However, even though humans and their behavior remain essential for operational performance, human factors in...

For overlapping operations, the ALVs may need to process an unload transaction after processing a load transaction or vice versa. In such situations, the ALVs have to move from one QC location to another QC location or from one SC location to another SC location. In this section, we adopt the...

Shuttle-based compact systems are new automated multi-deep unit-load storage systems with lifts that promise both low operational cost and large volume flexibility. In this paper, we develop novel queuing network models to estimate the performance of both single-tier and multi-tier shuttle-based...