To appropriately determine a picking system with good efficiency according to the content of an order.

When data 1 indicating a collection item of an article are inputted, a required time of a picking work along a plurality of picking systems is calculated respectively (step S1) based on reference required time 2, 3 in every working step previously set corresponding to a plurality of picking systems respectively. Then, the picking system having the shortest required time of a plurality of picking systems is determined as an execution system (step S2). Working instruction for collecting the collection item is outputted by the execution system (step S3). Thereby, the efficient picking system corresponding to the content of the order is appropriately determined.