Abstract: A method controls storage locations of products stored in storage containers in an automated storage and retrieval system operated by container handling vehicles. The storage and retrieval system comprises a grid structure with storage columns adapted for holding stacks of storage containers. The grid structure has a corresponding rail system above the storage columns for guiding movements of the vehicles adapted for transferring storage containers to and from the storage columns. Each vehicle comprises a vehicle controller connected to driving means for controlling movements of the vehicle along the rail system relative to movements of other vehicles. Controlling of container handling vehicles and storage locations of storage containers is handled by a main controller of the automated storage and retrieval system communicating with a Warehouse Management System configured to register each storage container to be stored and type of one or more products placed in the storage containers.