Product inspection device, product inspection method, and computer program

A method for inspecting a plurality of products, the method comprising:

• measuring, as a product measurement value, a characteristic value for each of the plurality of products that represents a predetermined characteristic of the plurality of products;
• calculating a standard deviation of measurement variations in measurement results;
• determining, based on a product standard defining an upper limit value and a lower limit value of the characteristic values for determining conformity/defectiveness of the plurality of products, whether each of the plurality of products is a conforming article based on whether the respective measured product measurement value falls within a range between the upper limit value and the lower limit value;
• calculating, based on the calculated measurement variations, a consumer risk that is a probability that any product of the plurality of products failing to satisfy the product standard will be erroneously determined as a conforming article by the measurement variations, a producer risk that is a probability that any products of the plurality of products satisfying the product standard will be erroneously determined as a defective article by the measurement variations;
• respectively and successively adding up the calculated consumer risk and the calculated producer risk;
• determining whether a number of products of the plurality of produces having undergone the adding has reached a predetermined number;
• and
• calculating, when the number of products having undergone the adding is determined to have reached the predetermined number, a final consumer risk and a final producer risk by dividing the added up consumer risk and the producer risk by the number of products having undergone the adding.

A non-transitory computer readable medium storing a computer program with computer executable instructions capable of being executed with a product inspection device for inspecting a plurality of products, the computer program including computer executable instructions for:

• measuring, as a product measurement value, a characteristic value for each of the plurality of products that represents a predetermined characteristic of the plurality of products;
• calculating a standard deviation of measurement variations in measurement results;
• determining, based on a product standard defining an upper limit value and a lower limit value of the characteristic values for determining conformity/defectiveness of the plurality of products, whether each of the plurality of products is a conforming article based on whether the respective measured product measurement value falls within a range between the upper limit value and the lower limit value;
• calculating, based on the calculated measurement variations, a consumer risk that is a probability that any product of the plurality of products failing to satisfy the product standard will be erroneously determined as a conforming article by the measurement variations, and a producer risk that is a probability that any product of the plurality of products satisfying the product standard will be erroneously determined as a defective article by the measurement variations;
• respectively and successively adding up the calculated consumer risk and the calculated producer risk;
• determining whether a number of products of the plurality of products having undergone the adding has reached a predetermined number;
• and
• calculating, when the added count determining means determines that the number of products having undergone the adding has reached the predetermined number, a final consumer risk and a final producer risk by dividing the added up consumer risk and the added up producer risk by the number of products having undergone the adding.