Patent ID: 7242994

Claim:
A method for drafting a production plan for a production line for a given period by use of a computer, said production line including a plurality of production processes and a salvage process, said salvage process disassembling products found to be defective in said production processes and returning salvaged parts to said production processes, said method comprising: an information collecting step of collecting yield information B j on products previously produced by said production line on each day j and obtaining an actual total supply quantity ratio C i,j and an actual salvage ratio D i,j for each production process i on each day j, said yield information B j , said actual total supply quantity ratio C i,j , and said actual salvage ratio D i,j being used to establish a salvage process calculation model; a new parts supply quantity recalculating step of recalculating the quantity X i,j of parts to be newly supplied to each production process i on each day j based on said product yield information B j on each day j, said actual total supply quantity ratio C i,j for each production process i on each day j, said actual salvage ratio D i,j for each production process i on each day j, the requested quantity A j of finished products on each day j, and a correction parameter F i,j for said actual total supply quantity ratio C i,j for each production process i on each day j, said product yield information B j , said actual total supply quantity ratio C i,j , and said actual salvage ratio D i,j being obtained at said information collecting step; and a production process load determining step of, to draft said production plan for said given period, determining the load on each production process of said production line based on said quantity X i,j of parts to be newly supplied to each process i on each day j in such a way that said requested quantity A j of finished products can be produced on each day j, said quantity X i,j being recalculated at said new parts supply quantity recalculating step.