An apparatus (101;2101) for identifying a path pattern of a plurality of devices that causes a defective product in a production line where a product is produced via the devices (10,11,12,13,14,15), the apparatus comprising: a production path extractor (112;2112) configured to extract a production path indicating the devices through which the product passes when it is produced and an order in which the product passes through the devices, based on product information transmitted from an apparatus for monitoring quality (302, 2302); a production path quality generator (113;2113) configured to generate a production path quality value indicating a quality of a group of products produced through the production path; a path pattern generator (114;2114) configured to generate a possible path pattern indicating the devices through which the product passes when it is produced and the order in which the product passes through the devices, in accordance with a number of indispensable devices indicating a number of devices that must be included in the path pattern; an association relationship generator (115;2115) configured to generate an association relationship between the production path and the path pattern; a path pattern quality estimator (116;2116) configured to estimate a path pattern quality value indicating a quality of the group of products produced through the production path included in the path pattern, based on the association relationship and the production path quality value; and a defective path pattern identifier (117;2117) configured to identify a defective path pattern for which the value of the path pattern quality is equal to or larger than a predetermined threshold value. a production path extractor (112;2112) configured to extract a production path indicating the devices through which the product passes when it is produced and an order in which the product passes through the devices, based on product information transmitted from an apparatus for monitoring quality (302, 2302); a production path quality generator (113;2113) configured to generate a production path quality value indicating a quality of a group of products produced through the production path; a path pattern generator (114;2114) configured to generate a possible path pattern indicating the devices through which the product passes when it is produced and the order in which the product passes through the devices, in accordance with a number of indispensable devices indicating a number of devices that must be included in the path pattern; an association relationship generator (115;2115) configured to generate an association relationship between the production path and the path pattern; a path pattern quality estimator (116;2116) configured to estimate a path pattern quality value indicating a quality of the group of products produced through the production path included in the path pattern, based on the association relationship and the production path quality value; and a defective path pattern identifier (117;2117) configured to identify a defective path pattern for which the value of the path pattern quality is equal to or larger than a predetermined threshold value.