Method and system of production planning

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 Bj on products previously produced by said production line on each day j and obtaining an actual total supply quantity ratio Ci,j and an actual salvage ratio Di,j for each production process i on each day j, said yield information Bj, said actual total supply quantity ratio Ci,j and said actual salvage ratio Di,j being used to establish a salvage process calculation model;
• a correction parameter calculating step of calculating a correction parameter fi,j for said actual total supply quantity ratio Ci,j for each production process i for each day j in such a way that the requested quantity Aj of finished products can be produced by said production line on each day j and furthermore an appropriate quantity OWi,j of stock can be obtained for each production process i on each day j, said actual total supply quantity ratio Ci,j being obtained at said information collecting step;
• a new parts supply quantity recalculating step of recalculating step of recalculating the quantity Xi,j of parts to be newly supplied to each production process i on each day j based on said product yield information Bj on each day j, said actual total supply quantity ratio Ci,j for each production process i on each day j, said actual salvage ration Di,j for each production process i on each day j, said requested quantity Aj of finished products on each day j, and a correction parameter Fi,j for each production process i on each day j obtained from said correction parameter fi,j for each production process i on each day j calculated at said correction parameter calculating step, said product yield information Bj, said actual total supply quantity ratio Ci,j, and said actual salvage ration Di,j being obtained at said information collection step, said correction parameter Fi,j being set between upper and lower limit values;
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• 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 Xi,j of parts to be newly supplied to each process i on each day j in such a way that said requested quantity Aj of finished products can be produced on each day j, said quantity Xi,j being recalculated at said new parts supply quantity recalculating step.

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 Bj on products previously produced by said production line on each day j and obtaining an actual total supply quantity ratio Ci,j and an actual salvage ratio Di,j for each production process i on each day j, said yield information Bj, said actual total supply quantity ratio Ci,j, and said actual salvage ratio Di,j being used to establish a salvage process calculation model;
• a correction parameter calculating step of calculating a correction parameter fi,j for said actual total supply quantity ratio Ci,j for each production process i for each day j in such a way that the requested quantity Aj of finished products can be produced by said production line on each day j and furthermore an appropriate quantity OWi,j of stock can be obtained for each production process i on each day j, said actual total supply quantity ratio Ci,j being obtained at said information collecting step;
• a correction parameter setting step of setting said correction parameter fi,j at between upper and lower limit values, said correction parameter fi,j being calculated for each production process i for each day j at said correction parameter calculating step;
• a new parts supply quantity recalculating step of recalculating step of, in accordance with the equation Xi,j=((Fi,j*Ci,j)−((1−Bj)*Di,j))*(Aj/Bj), recalculating the quantity Xi,j of parts to be newly supplied to each production process i on each day j based on said product yield information Bj on each day j, said actual total supply quantity ratio Ci,j for each production process i on each day j, said actual salvage ration Di,j for each production process i on each day j set at said correction parameter setting step, said product yield information Bj, said actual the quantity Xi,j of parts to be newly supplied to each production process i on each day j based on said product yield information Bj on each day j, said actual total supply quantity ratio Ci,j for each production process i on each day j, said actual salvage ratio Di,j for each production process i on each day j, said requested quantity Aj of finished products on each day j, and a correction parameter Fi,j for each production process i on each day j obtained from said correction parameter fi,j for each production process i on each day j calculated at said correction parameter calculating step, said product yield information Bj, said actual total supply quantity ratio Ci,j, and said actual salvage ratio Di,j being obtained at said information collecting step, said correction parameter Fi,j being set between upper and lower limit values;
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• 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 Xi,j of parts to be newly supplied to each production process i on each day j in such a way that said requested quantity Aj of finished products can be produced on each day j, said quantity Xi,j being recalculated at said new parts supply quantity recalculating step.

A system 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 system comprising:

• an information collecting unit for collecting yield information Bj on products previously produced by said production line on each day j and obtaining an actual total supply quantity ratio Ci,j and an actual salvage ratio Di,j for each production process i on each day j, said yield information Bj, said actual total supply quantity ratio Ci,j, and said actual salvage ratio Di,j being used to establish a salvage process calculation model;
• a new parts supply quantity recalculating unit for recalculating the quantity Xi,j of parts to be newly supplied to each production process i on each day j based on said product yield information Bj on each day j, said actual total supply quantity ratio Ci,j for each production process i on each day j, said actual salvage ratio Di,j for each production process i on each day j, the requested quantity Aj of finished products on each day j, and a correction parameter Fi,j for said actual total supply quantity ratio Ci,j for each production process i on each day j, said product yield information Bj, said actual total supply quantity ratio Ci,j, and said actual salvage ratio Di,j being obtained by said information collecting unit;
• and
• a production process load determining unit for, to draft said production plan for said given period, determining the load on each production process of said production line based on said quantity Xi,j of parts to be newly supplied to each production process i on each day j in such a way that said requested quantity Aj of finished products can be produced on each day j, said quantity Xi,j being recalculated by said new parts supply quantity recalculating unit.

A system for drafting a production plan for a production line for a give 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 system comprising:

• an information collecting unit for collecting yield information Bj on products previously produced by said production line on each day j and obtaining an actual total supply quantity ratio Ci,j and an actual salvage ratio Di,j for each production process i on each day j, said yield information Bj, said actual total supply quantity ratio Ci,j, and said actual salvage ratio Di,j being used to establish a salvage process calculation model;
• a correction parameter calculating unit for calculating a correction parameter fi,j for said actual total supply quantity ratio Ci,j for each production process i for each day j in such a way that the requested quantity Aj of finished products can be produced by said production line on each day j and furthermore an appropriate quantity OWi,j of stock can be obtained for each production process i on each day j, said actual total supply quantity ratio Ci,j being obtained by said information collecting unit;
• a new parts supply quantity recalculating unit for recalculating the quantity Xi,j of parts to be newly supplied to each production process i on each day j based on said product yield information Bj on each day j, said actual total supply quantity ratio Ci,j for each production process i on each day j, said actual salvage ratio Di,j for each production process i on each day j, said requested quantity Aj of finished products on each day j, and a correction parameter Fi,j for each production process i on each day j obtained from said correction parameter fi,j for each production process i on each day j calculated by said correction parameter calculating unit, said product yield information Bj, said actual total supply quantity ratio Ci,j, and said actual salvage ratio Di,j being obtained by said information collecting unit, said correction parameter Fi,j being set between upper and lower limit values;
• and
• a production process load determining unit for, to draft said production plan for said given period, determining the load on each production process of said production line based on said quantity Xi,j of parts to be newly supplied to each production process i on each day in such a way that said requested quantity Aj of finished products can be produced on each day j, said quantity Xi,j being recalculated by said new parts supply quantity recalculating unit.

A system 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 system comprising:

• an information collecting unit for collecting yield information Bj on products previously produced by said production line on each day j and obtaining an actual total supply quantity ratio Ci,j and an actual salvage ratio Di,j for each production process i on each day j, said yield information Bj, said actual total supply quantity ratio Ci,j, and said actual salvage ratio Di,j being used to establish a salvage process calculation model;
• a correction parameter calculating unit for calculating a correction parameter fi,j for said actual total supply quantity ratio Ci,j for each production process i for each day j in such a way that the requested quantity Aj of finished products can be produced by said production line on each day j and furthermore an appropriate quantity OWi,j of stock can be obtained for each production process i on each day j, said actual total supply quantity ratio Ci,j being obtained by said information collecting unit;
• a correction parameter setting unit for setting said correction parameter fi,j at between upper and lower limit values, said correction parameter fi,j being calculated for each production process i for each day j by said correction parameter calculating unit;
• a new parts supply quantity recalculating unit for, in accordance with the equation Xi,j=(Fi,j*Ci,j)−((1−Bj)*Di,j)*(Aj/Bj), recalculating the quantity Xi,j of parts to be newly supplied to each production process i on each day j based on said product yield information Bj on each day j, said actual total supply quantity ratio Ci,j for each production process i on each day j, said actual salvage ratio Di,j for each production process i on each day j, said requested quantity Aj of finished products on each day j, and a correction parameter Fi,j for each production process i on each day j obtained from said correction parameter fi,j for each production process i on each day j set by said correction parameter setting unit, said product yield information Bj, said actual total supply quantity ratio Ci,j, and said actual salvage ratio Di,j being obtained by said information collecting unit, said correction parameter Fi,j being set between said upper and lower limit values;
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• a production process load determining unit for, to draft said production plan for said given period, determining the load on each production process of said production line based on said quantity Xi,j of parts to be newly supplied to each production process i on each day j, said quantity Xi,j being recalculated by said new parts supply quantity recalculating unit.