Storage, retrieval, order sortation and packout

An order fulfillment system comprising:

• first function sorting system comprises first function vehicles traveling on a first function platform raised from a surface for transporting and depositing first function articles to be sorted into a plurality of first function sort receptacles in response to commands;
• an article storage and retrieval system (ASRS) juxtaposed to the first function sorting system such that a footprint occupied by the first function sorting system is adjacent to the footprint occupied by the ASRS, the article storage and retrieval system comprising a three-dimensional array of storage spaces from which the first function articles to be sorted are automatically retrievable by one or more retrieval mechanisms in response to commands;
• and,
• a controller configured to:
• direct a retrieval mechanism of the article storage and retrieval system to move a storage bin containing a first function article to an output station;
• and,
• direct a first function vehicle to transport and deposit the first function article collected from the storage bin at the output station into a first function sort receptacle.