Abstract: The method of planning a production schedule of the present invention has a production order preparing unit which, in response to an order, the completed product stock is allocated to the previous production schedule planned before an order change, and which prepares a production order. The production schedule which is previously planned is allocated to the production order which has been subjected to allocation of the completed product stock to the order, in accordance with information such as the product identification, the quantity, and the delivery time. The allocated portion of the previous production schedule is used as it is in the current production schedule.

Abstract: A radiographic test is conducted on a welded portion of a pipe or the like to form a radiographic image, which is introduced into a computer. Volumetric defects and planar defects in the radiographic image are emphasized and extracted by separate methods to obtain a volumetric candidate defect image and a planar candidate defect image. The candidate defect images are then combined to form a single image in which defects can be easily identified. Features of defects in the images are measured, and a set of interference rules is applied to the measured features. Each inference rule gives a degree of certainty that a defect is of a certain type. The degrees of certainty determined by a plurality of the rules are collated to obtain a total degree of certainty, and the type of a defect is inferred from the total degree of certainty.