Computer readable storage medium for work-in-process schedules

Abstract

A computer readable storage medium for work in progress (WIP) schedules in semiconductor manufacturing facility. After determining starting and ending dates of predetermined schedule periods for generating WIP schedules, remaining days are determined for completing at least one wafer lot associated with predetermined product from the starting date. A starting process stage for the wafer lot is determined at the starting date based on the remaining days, and an ending process stage for the wafer lot at the end of the ending date. Wafer numbers are assigned to each process stage of schedule times in proportion to process times of each stage in view of total process time for the schedule period, and by repeating the above steps for one or more other wafer lots under production, a total wafer number assigned to each stage is determined and the WIP schedule for the schedule period is obtained.

1 . A computer readable storage medium encoded with computer program code, wherein, when the computer program code is executed by a processor, the processor performs a method for generating a work in progress (WIP) schedule in a semiconductor manufacturing facility, comprising the steps of: 
 receiving starting and ending dates of a predetermined schedule period for generating the WIP schedule;    determining remaining days for completing at least one wafer lot associated with a predetermined product from the starting date;    determining a starting process stage for the wafer lot at the beginning of the starting date based on the remaining days;    determining an ending process stage for the wafer lot at the end of the ending date;    assigning wafer numbers to each process stage between the starting and the ending process stages of the schedule time in proportion to a process time of each stage in view of a total process time for the schedule period; and    generating the WIP schedule for the schedule period after repeating the above steps for one or more other wafer lots under production to determine a total wafer number assigned to each stage.    
   
   
       2 . The computer readable storage medium of  claim 1 , wherein the starting dates and the ending dates are the same.  
   
   
       3 . The computer readable storage medium of  claim 1 , wherein the step for determining a starting process stage further includes steps of: 
 receiving a process time for each process stage to complete the wafer lot; and    identifying the starting process stage along a remaining process time line indicating remaining time for completing the wafer lot based on the determined remaining days and a total process time for completing the wafer lot.    
   
   
       4 . The computer readable storage medium of  claim 3 , wherein the step for identifying the starting process stage further includes steps of: 
 scaling the remaining days by a cycle time factor to obtain a time point; and    determining the starting process stage by identifying the time point along the remaining process time line.