Patent ID: 7693593

Claim:
A production planning method for extracting a cause parameter item of a manufacturing production unavailability number by using production capacity evaluation calculation, characterized by comprising: a production capacity evaluation step of calculating on a computer, a previous manufacturing production availability number of a previous production plan and a current manufacturing production availability number of a current production plan by using a production capacity evaluation calculation for a request day and a product; a target production line extraction step of extracting using the computer, a target production line to be used in a production plan of a product in which a change occurs by comparing the previous manufacturing production availability number with the current manufacturing production availability number for each request day and each product calculated at the production capacity evaluation step; a parameter item extraction step of extracting using the computer, from the production line extracted at the target production line extraction step, a parameter item to be used in the production capacity evaluation calculation with respect to all products; a cause parameter list creation step of specifying at least one of the parameter items as a cause of a change by difference-comparing data at a time of previous production planning with data at a time of current production planning for each parameter item extracted at the parameter item extraction step and listing the specified cause parameter item, where k denotes an argument of a cause parameter list; a recalculation step of recalculating using the computer, a manufacturing production availability number k for each of the specified cause parameter items by using the production capacity evaluation calculation and by, based on the cause parameter list created at the cause parameter list creation step, sequentially changing cause parameter items other than the specified cause parameter item to data at the time of the previous production planning and inputting data at the time of the current production planning with respect to the specified cause parameter item; an influence index calculation step of calculating using the computer, an influence index k given to the manufacturing production unavailability number by the specified cause parameter item k based on a following expression and based on the manufacturing production availability number k of each of the specified cause parameter items recalculated at the recalculation step: influence index k =(previous manufacturing production availability number −manufacturing production availability number k )/(previous manufacturing production availability number−current manufacturing production availability number); and displaying the calculated influence index k on a display device.