Container handling vehicle elevator

A method of operating an automated storage and retrieval system comprising:

• a framework structure having a plurality of internal and peripheral upright members arranged to define a storage grid comprising multiple storage columns for storing storage containers on top of each other in vertical stacks,
• at least one container handling vehicle,
• wherein the upright members of the framework structure are interconnected at their upper ends by a rail system arranged to guide at least one container handling vehicle thereon, the container handling vehicle being configured to raise storage containers from, and lower storage containers into, the storage columns, and to transport the storage containers horizontally above the storage columns, wherein the peripheral upright members of the framework structure define an horizontal periphery of the framework structure, and
• a vehicle elevator comprising:
• a vertically extending support,
• a platform comprising a horizontally extending structure arranged to carry the container handling vehicle and a connection device moveably attaching the platform to the vertically extending support, and
• a lift mechanism arranged to move the platform between a first lift stop position, which establishes access between the platform and the rail system, and a second lift stop position which is arranged within an accessing area such that a human operator/service personnel and/or robot can perform in-situ maintenance on the container handling vehicle while the container handling vehicle is arranged on the platform, and wherein the first and second lift stop positions are arranged vertically offset, and
• wherein the method comprises:
• i) moving the container handling vehicle from the rail system onto the platform which is positioned in the first lift position,
• ii) moving the platform into the second lift stop position, enabling access to the container handling vehicle for a human operator and/or robot to perform in-situ maintenance on the container handling vehicle.