Abstract: A multi-storey goods storage arrangement comprising a plurality of levels of storage lines (12) arranged in parallel and transport lines (18) extending between opposing ends of said storage lines (12). It also comprises a plurality of picking lines (28), each picking line replacing a storage line (12) at one level at one side of a transport line (18), and a picking robot (30), each picking robot (30) operable along and over a picking line (28). A method of providing a mixed load carrier of different items stored on load carriers (14) on a plurality of levels of storage lines (12) by operating at least one picking robot (30) along a picking line (28) replacing a storage line (12) at one level at one side of a transport line (18). The picking robot (30) being arranged to pick up automatically items from a first load carrier (43) and to place automatically the items on a second load carrier (42, 44) forming a mixed load carrier.