A method receives store inventory batch updates from a plurality of retail stores and divides each batch update into a stream of smaller messages, each smaller message referring only to a single product and including the identifier for the retail store, the identifier for the product, the quantity of the product on the sales floor of the retail store and the quantity of the product in the backroom of the retail store. The stream of smaller messages are applied to parallel processing such that a plurality of smaller messages can be processed at the same time, the parallel processing of each smaller message determining a quantity of the respective product that must be moved to the sales floor to satisfy at least one restocking rule given the quantities of the product on the sales floor in the smaller message and storing the quantity in a database.