US 6,633,791 B1 · Dispatching system with dynamically forward loading (DFL) intensity to solve nonlinear wafer out problem

Abstract

Calculate the WIPi for a stage STkk for each lot Li in a queue of lots being processed in a production line between the stage STkk and an end point, where “i” is a positive integer representing the position of the lot Li in the queue, and where “kk” is a positive integer indicating the sequential position of the stage STkk (location along the production line) from the beginning to the end of a predetermined portion of the production line. Calculate remaining scheduled cycle time (RCTi) for each lot Li. Calculate consumed scheduled cycle time (CSTi) for each lot Li. Calculate (WIPi*RCTi) for each lot Li. Calculate (WIP*CSTi) for each lot Li. Sum WIPi*RCTi for all lots Li of a stage. Sum WIPi*CST for all lots Li of a stage. Calculate the Index of Dynamic Forward Loading Intensity (IDFL) for each stage STkk by dividing the (Sum WIPi*RCTi, for all lots of the stage) by the (Sum WIPi*CSTi, for all lots of the stage) where kk is a positive integer indicating the location of the stage from the beginning to the end of the production line. Adjust the dispatching order of lots based on the rankings of the stages of the production IDFL line, with lowest IDFL ratings having priority.

Claims7

Dependent claims

A method for determining an Index of Dynamic Forward Loading (IDFL) for a stage on a production line comprising:

calculate a Work In Processi (WIPi) for a stage STkk for each lot Li in a queue of lots being processed in a production line between said stage STkk and end point, where “i” is a positive integer representing the position of said lot Li in said queue, and where “kk” is a positive integer indicating the sequential position of the stage STkk in a location along said production line from the beginning to the end of a predetermined portion of said production line,
calculate remaining scheduled cycle time (RCTi) for each lot Li,
calculate consumed scheduled cycle time (CSTi) for each lot Li,
calculate WIPi*RCTi for each lot Li,
calculate WIPi*CSTi for each lot Li,
summing WIPi*RCTi for all lots Li of a stage,
summing WIPi*CSTi for all lots Li of a stage,
calculate an Index of Dynamic Forward Loading (IDFL) Intensity for each stage STkk by dividing the Sum WIPi*RCTi, for all lots of the stage STkk, by the Sum WIPi*CSTi, for all lots of the stage STkk, where kk is a positive integer indicating the location of the stage from the beginning to the end of said production line, and
adjust dispatching order of lots based on IDFL Intensity of all stages of the production line, with lowest IDFL Intensity having priority.

6 more elements

A system for determining an Index of Dynamic Forward Loading Intensity (IDFL) for a stage on a production line comprising:

means for calculating a Work in Process (WIPi) for a stage STkk for each lot Li in a queue of lots being processed in a production line between said stage STkk and end point, where “i” is a positive integer representing the position of said lot Li in said queue, and where “kk” is a positive integer indicating the sequential position of the stage STkk location along said production line from the beginning to the end of a predetermined portion of said production line,
means for calculating the remaining scheduled cycle time (RCTi) for each lot Li,
means for calculating consumed scheduled cycle time (CSTi) for each lot Li,
means for calculating WIPi*RCTi for each lot Li,
means for calculating WIPi*CSTi for each lot Li,
means for summing WIPi*RCTi for all lots Li of a stage
means for summing WIPi*CSTi for all lots Li of a stage,
means for calculating an Index of Dynamic Forward Loading (IDFL) Intensity for each stage STkk by dividing the Sum WIPi*RCTi, for all lots of the stage STkk by the Sum WIPi*CSTi, for all lots of the stage STkk, where kk is a positive integer indicating the location of the stage from the beginning to the end of said production line, and
means for adjusting dispatching order of lots based on IDFL Intensity of all stages of the production lines with lowest IDFL Intensity having priority.

6 more elements

Dependencies are inferred from the claim text.

Dispatching system with dynamically forward loading (DFL) intensity to solve nonlinear wafer out problem

Life of this patent

Dispatching system with dynamically forward loading (DFL) intensity to solve nonlinear wafer out problem

Life of this patent

Abstract

Claims7