Abstract
A method and system for rearranging containers in a storage and retrieval system comprising a three-dimensional storage grid structure for storing items. The grid structure forms vertical storage columns each having a horizontal area defined by the size of an access opening of the vertical storage columns. The framework structure comprises a rail system arranged above the storage columns. The method comprises checking if there are free spaces along at least one of the edges of the grid of the storage and retrieval system, checking if there are enough free spaces in the non-edge cells of the grid of the storage and retrieval system to perform normal operations, and performing rearranging if there are free spaces along at least one of the edges of the grid of the storage and retrieval system and there is not enough free spaces in the non-edge cells of the grid of the storage and retrieval system to perform normal operations.