An apparatus for identifying a path pattern of devices that produces a defective product in a production line where a product is produced via a plurality of device is provided. The device is configured to estimate a path pattern quality indicating a quality of a group of products produced through a production path included in a path pattern, based on a production path quality and an association relationship between a path pattern and a production path indicating devices via which the product is produced and an order of passing through the devices; and to identify a path pattern suspected to be defective based on the estimated path pattern quality.