An operation unit executes a process for calling to a main memory first data representative of a result of equipment QC applied to a production unit. A process for reading out to the main memory an amount of change in failure in accordance with particle numbers calculated for individual defect sizes from second inspection data representative of a result of equipment QC is applied to the production unit. Electrical test data of a product processed by the production unit during a period inclusive of the time that the second inspection is carried outis also read to the main memory. A process is also executed for using the amount of change in failure in accordance with the calculated particle numbers and the particle numbers for individual sizes determined from the first inspection data to determine an impact on the product by particles generated in the production equipment when the first inspection data is detected.