Method of production control and method of manufacturing electronic apparatus

A method of production control used for a group of production steps belonging to a production line for two or more product types in the presence of a condition that a history of an apparatus used for processing one product type at one of the production steps limits Processing of one product type at another of the group of production steps to a certain apparatus, the method comprising the steps of:

• categorizing products into product types according to the apparatus used or scheduled to be used at a first production step that places the condition that limits use of the apparatus;
• determining a tentative target quantity to be processed and/or a target quantity to be processed for each of the categorized product types;
• controlling the production line based on the tentative target quantity to be processed and/or the target Quantity to be processed,
• the tentative target quantity to be processed is set for each of the product types at a production step under the condition that limits use of apparatus on an assumption that only one product type flows through the production step and on an assumption that a mixture of the product types flow through the production step;
• and
• the target quantity to be processed for each product type is determined such that a ratio of the target quantity to be processed of each product type is equal to a ratio of a quantity of work in process that can be actually processed for the product type, such that the sum of the target quantities to be processed of the product types is at a maximum value that is equal to or smaller than the sum of the tentative target quantities to be processed, and such that the target quantity to be processed for each product type is at a maximum value that is equal to or smaller than the tentative target quantity to be processed for the product type.

A method of production control used for a group of production steps belonging to a production line for two or more product types in the presence of a condition that a history of an apparatus used for processing one product type at one of the production steps limits processing of one product type at another of the group of production steps to a certain apparatus, the method comprising the steps of:

• categorizing products into product types according to the apparatus used or scheduled to be used at a first production step that places the condition that limits use of the apparatus;
• determining a tentative target quantity to be processed and/or a target quantity to be processed for each of the categorized product types;
• controlling the production line based on the tentative target quantity to be processed and/or the target quantity to be processed, the tentative target quantity to be processed of one product type at one production step is set greater than a quantity of products to form one batch of the product type or a quantity of products that is equal to or smaller than the quantity of products to form a batch and that is obtained by subtracting a quantity of products to form one lot or one unit for transportation as a part of a batch from the quantity of products to form a batch;
• and
• the tentative target quantity to be processed is set as the target quantity to be processed when a quantity of work in process that can be processed at the production step is equal to or greater than the tentative target quantity to be processed.

A method of production control for a production line having a plurality of production steps, comprising the steps of:

• setting a tentative target quantity to be processed at a major production step in advance;
• setting the tentative target quantity to be processed as a target quantity to be processed when a quantity of work in process that can be actually processed is equal to or greater than the tentative target quantity to be processed;
• setting a quantity of work in process that can be processed as the target quantity to be processed when the quantity of work in process that can be actually processed is smaller than the tentative target quantity to be processed;
• controlling the production line based on the target quantity to be processed.
• calculating a tentative target quantity to be processed at a shipping step of a production line by determining a quantity to be recovered from a planned cumulative quantity shipped of each product type in a period starting from a day at an end of a production plan until a day to start a calculation of the target quantity to be processed minus the actual cumulative quantity shipped divided by the recovery period and by adding the quantity to be recovered to an initial planned quantity to be shipped in the period from the starting day until the day on which the recovery is scheduled to be completed;
• and
• calculating the tentative quantity to be processed added with the quantity to be recovered for each product type when a plurality of product types flow on the production line.

A method of manufacturing an electronic apparatus utilizing a method of production control comprising the steps of:

• setting a tentative target quantity to be processed at a major production step in advance;
• setting the tentative target quantity to be processed as a target quantity to be processed when a quantity of work in process that can be actually processed is equal to or greater than the tentative target quantity to be processed;
• setting a quantity of work in process that can be processed as the target quantity to be processed when the quantity of work in process that can be actually processed is smaller than the tentative target quantity to be processed;
• and
• controlling the production line based on the target quantity to be processed.