This field allows you to specify how the system should deal with line items when automatically generating purchase orders. Selecting this option will allow the system to consolidate the total requirements per line item. This is the preferred method.
Otherwise, items to be purchased will be broken down into more detail. This detail may be useful if you generate purchase orders automatically from "selected invoices" rather than "past sales" and you need to see the orders from each of your customers that went into the system generating the purchase order.