We introduce and develop models for very high density physical goods storage systems, which are characterized by sometimes having to move interfering items in order to gain access to desired items. We describe a simple, but effective, algorithm to densely fill rectangular storage spaces, subject to a constraint on the number of interfering items. We also prove an upper bound on the storage density for any rectangular space, including traditional warehouses.
Acknowledgements
The author thanks the Office of Naval Research for supporting this work. John Bartholdi and Don Eisenstein offered helpful comments, and Samir Amiouny produced an example layout (for which he was awarded the handsome sum of $100) that led to a refinement of the FILL-AND-ROTATE algorithm. Joe Skufca provided significant insights into the proof of Theorem 1.