System and Method Providing Levelness of a Production Schedule

Abstract

A system and method are disclosed for providing levelness of a production schedule. The system includes a computer configured to access demand data of one or more items to be processed within a sequence of tasks, access the demand data of the one or more items, calculate one or more time intervals for each of the one or more items, and calculate a weighted average for each of the one or more items. The computer is further configured to calculate a time ratio according to the sequence of tasks by calculating the average of the calculated time intervals and the calculated weighted averages and calculating a minimum ratio of an adjusted time interval for each of the one or more items and the calculated weighted averages. The computer is still further configured to generate a production schedule based on a sequence of tasks having a predetermined calculated time ratio.

What is claimed is: 
     
         1 . A system providing levelness of a production schedule, comprising:
 a database that stores demand data of one or more items to be processed within a sequence of tasks; and   a computer coupled with the database and configured to:
 access the demand data of the one or more items; 
 calculate one or more time intervals for each of the one or more items; 
 calculate a weighted average for each of the one or more items; 
 calculate a time ratio according to the sequence of tasks by: 
 calculating the average of the calculated time intervals and the calculated weighted averages; and 
 calculating a minimum ratio of an adjusted time interval for each of the one or more items and the calculated weighted averages, upper bounded by unity; 
   generate a production schedule based on a sequence of tasks having a predetermined calculated time ratio; and   store the generated production schedule in the database.   
     
     
         2 . The system of  claim 1 , wherein the computer is further configured to:
 determine a total number of tasks within the sequence of tasks and a total number of tasks for each of the one or more items based on the accessed demand data of the one or more items.   
     
     
         3 . The system of  claim 2 , wherein the one or more time intervals is determined by calculating the ratio of the total number of tasks within the sequence of tasks and the total number of tasks for each of the one or more items. 
     
     
         4 . The system of  claim 1 , wherein the computer is further configured to:
 determine a number of subsequences of tasks within the sequence of tasks for each of the one or more items which have at least [T A ] tasks, where [T A ] is the largest whole number smaller than or equal to the time interval of the item.   
     
     
         5 . The system of  claim 4 , wherein the computer is further configured to:
 for each of the subsequence of tasks within the sequence of tasks calculate a weight of each of the one or more items based on:
   1+[| T   A   −X|]   
   wherein T A  is representative of the time interval for each of the one or more items and X is representative of the number of tasks within the subsequence of tasks.   
     
     
         6 . The system of  claim 5 , wherein the computer is further configured to:
 calculate a weighted average for each of the one or more items in accordance with the determined number of tasks within the subsequence of tasks and the calculated weight of each of the one or more items.   
     
     
         7 . The system of  claim 1 , wherein the computer is further configured to determine a new order of tasks within the sequence of tasks. 
     
     
         8 . A computer-implemented method of providing levelness of a production schedule, comprising:
 accessing, by a computer, demand data of one or more items to be processed within a sequence of tasks;   calculating, by the computer, one or more time intervals for each of the one or more items;   calculating, by the computer, a weighted average for each of the one or more items;   calculating, by the computer, a time ratio according to the sequence of tasks by:
 calculating the average of the calculated time intervals and the calculated weighted averages; and 
 calculating a minimum ratio of an adjusted time interval for each of the one or more items and the calculated weighted averages, upper bounded by unity; 
   generating, by the computer, a production schedule based on a sequence of tasks having a predetermined calculated time ratio; and   storing, by the computer, the generated production schedule in the database.   
     
     
         9 . The method of  claim 8 , further comprising:
 determining a total number of tasks within the sequence of tasks and a total number of tasks for each of the one or more items based on the accessed demand data of the one or more items.   
     
     
         10 . The method of  claim 9 , wherein the one or more time intervals is determined by calculating the ratio of the total number of tasks within the sequence of tasks and the total number of tasks for each of the one or more items. 
     
     
         11 . The method of  claim 8 , further comprising:
 determining a number of subsequences of tasks within the sequence of tasks for each of the one or more items which have at least [T A ] tasks, where [T A ] is the largest whole number smaller than or equal to the time interval of the item.   
     
     
         12 . The method of  claim 11 , further comprising:
 for each of the subsequences of tasks within the sequence of tasks calculating a weight of each of the one or more items based on:
   1+[| T   A   −X|]   
   wherein T A  is representative of the time interval for each of the one or more items and X is representative of the number of tasks within the subsequence of tasks.   
     
     
         13 . The method of  claim 12 , further comprising:
 calculating a weighted average for each of the one or more items in accordance with the determined number of tasks within the subsequence of tasks and the calculated weight of each of the one or more items.   
     
     
         14 . The method of  claim 8 , further comprising:
 determining a new order of tasks within the sequence of tasks.   
     
     
         15 . A non-transitory computer-readable medium embodied with software providing levelness of a production schedule, the software when executed using one or more computers is configured to:
 access demand data of one or more items to be processed within a sequence of tasks;   calculate one or more time intervals for each of the one or more items;   calculate a weighted average for each of the one or more items;   calculate a time ratio according to the sequence of tasks by:
 calculating the average of the calculated time intervals and the calculated weighted averages; and 
 calculating a minimum ratio of an adjusted time interval for each of the one or more items and the calculated weighted averages, upper bounded by unity; 
   generate a production schedule based on a sequence of tasks having a predetermined calculated time ratio; and   store the generated production schedule in the database.   
     
     
         16 . The non-transitory computer-readable medium of  claim 15 , wherein the software is further configured to:
 determine a total number of tasks within the sequence of tasks and a total number of tasks for each of the one or more items based on the accessed demand data of the one or more items.   
     
     
         17 . The non-transitory computer-readable medium of  claim 16 , wherein the one or more time intervals is determined by calculating the ratio of the total number of tasks within the sequence of tasks and the total number of tasks for each of the one or more items. 
     
     
         18 . The non-transitory computer-readable medium of  claim 15 , wherein the software is further configured to:
 determine a number of subsequences of tasks within the sequence of tasks for each of the one or more items which have at least [T A ] tasks, where [T A ] is the largest whole number smaller than or equal to the time interval of the item.   
     
     
         19 . The non-transitory computer-readable medium of  claim 18 , wherein the software is further configured to:
 for each of the subsequence of tasks within the sequence of tasks calculate a weight of each of the one or more items based on:
   1+[| T   A   −X|]   
   wherein T A  is representative of the time interval for each of the one or more items and X is representative of the number of tasks within the subsequence of tasks.   
     
     
         20 . The non-transitory computer-readable medium of  claim 19 , wherein the software is further configured to:
 calculate a weighted average for each of the one or more items in accordance with the determined number of tasks within the subsequence of tasks and the calculated weight of each of the one or more items.