Patent ID: 8825190

Claim:
A priority calculation device which calculates a priority of each of lots to be introduced into a manufacturing stage, comprising: a storage unit which stores: demand information which determines a product type and a demand ratio of the product type during a predetermined period; and process stand-by state information which determines, for each of manufacturing stages, a lot waiting for a processing in the manufacturing stage, a product for which the lot is used, and a quantity of parts included in the lot; and a control unit, wherein the control unit is configured to perform, for each of the manufacturing stages, a processing for determining, from the process stand-by state information, the lot waiting for the processing in the manufacturing stage, the product type for which the lot is used, and the quantity of the parts included in the lot, and assigning the priority to each of the lots so that the lot for which a product-type-basis ratio of the parts included in a lot pending in the processing of the manufacturing stage and processings subsequent thereto, the product-type-basis ratio being obtained when the determined lot is introduced into the manufacturing stage, becomes closer to a product-type-basis demand ratio determined by the demand information is preferentially introduced into the manufacturing stage; wherein the control unit is further configured to: calculate, for each of the manufacturing stages, a first Euclidean distance between the product-type-basis ratio of the parts included in the lot pending in the processing of the manufacturing stage and the subsequent processings and the product-type-basis demand ratio determined by the demand information; determine, for each of the manufacturing stages, the lot waiting for the processing in the manufacturing stage, the product type for which the lot is used, and the quantity of the parts included in the lot from the process stand-by state information, and calculate, for each of the determined lots, a second Euclidean distance between the product-type-basis ratio of the parts included in the lot pending in the processing of the manufacturing stage and the subsequent processings, the product-type-basis ratio being obtained when the determined lot is introduced into the manufacturing stage, and the product-type-basis demand ratio determined by the demand information; calculate an improvement amount by which the first Euclidean distance is improved into the second Euclidean distance, for each of the lots in each of the manufacturing stages; and assign, in each of the manufacturing stages, the priority to each of the lots so that the lot having the larger improvement amount is preferentially introduced into the manufacturing stage.