Method for performing dynamic re-scheduling of fabrication plant

Information

  • Patent Grant
  • 6434443
  • Patent Number
    6,434,443
  • Date Filed
    Monday, May 17, 1999
    25 years ago
  • Date Issued
    Tuesday, August 13, 2002
    22 years ago
Abstract
A method/system for performing dynamic re-scheduling of priorities of work-in-process in a fabrication plant for manufacturing of a product is provided. It reads a key stage report for the work-in-process and a master production schedule for the work-in-process from stored data. It generates a master production schedule report from the key stage report and the master production schedule following only Due_Date data for the work-in-process, and generates a work-in-process distribution matrix for integrating the master production schedule report with work-in-process quantity data within a deliverable cycle time; allocates selected lots from the work-in-process distribution matrix using a snake pattern method to allocate the selected lots from the matrix, and changes the due date for the selected lots of the work-in-process selected by the snake pattern method. It generates a final re-scheduling table for the work-in-process including the selected lots.
Description




BACKGROUND OF THE INVENTION




1. Field of the Invention




This invention relates to dynamic scheduling of workflow for a manufacturing plant and more particularly to optimizing the automation of scheduling of work in a plant processing a product such as semiconductor wafers.




2. Description of Related Art




Liu, C.; Thongmee, S.; and Hepburn, P. “A Methodology for Improving On-Time Delivery and Load Leveling Starts” 1995 IEEE/Semi Advanced Semiconductor Manufacturing Conference, pp. 95-100 (1995) describes methods for simulation-based production scheduling and planning of Work-In-Process (WIP).




Murty, S. V.; Bienvenu, J. W. “Global Planning at Harris Semiconductor” 1995 International Symposium on Semiconductor Manufacturing, pp. 18-23 (1995) describes a requirements planning system for a semiconductor specific planning engine that scans the entire production pipeline.




Hoitomt, D. J.; Luh, P. B. “Scheduling a Batch Processing Facility” Proceedings of the 1992 IEEE International Conference of Robotics and Automation” Nice France, (1992) pp 1167-1172 describes scheduling in a batch processing facility such as a “heat treat oven” for processing non-identical parts concurrently (batch composition) and determining beginning times for individual batches (batch sequencing). In some cases, composition is determined by assigning parts to batches according to Earliest Due Date (EDD). It states that the solution to the Lagrangian relaxation dual problem is a lower bound on the cost of the optimal schedule; and if assumptions are relaxed the EDD rule becomes a heuristic for solving the batch composition problem and the same batch sequencing algorithm can be used for making a schedule. It was to be used for improving delivery times where bottlenecks exist in batch processing facilities.




U.S. Pat. No. 5,612,886 of Weng for “Method and System for Dynamic Dispatching in Semiconductor Manufacturing Plants” shows a method for dynamic dispatching in semiconductor plants.




U.S. Pat. No. 5,546,326 of Tai et al. for “Dynamic Dispatching Rule that Uses Long Term Due Date and Short Term Queue Time to Improve Delivery Performance” discloses a dynamic dispatching rule.




SUMMARY OF THE INVENTION




It is an object of this invention to provide a method for changing the Due_Date (DD) of Work-In-Process (WIP) while at the same time assuring that the flow rate of the production line (wafer output) is linear. Product Control (PC) only uses the Required_Date (RD) based on manufacturing experience (e.g. a target of 2 days/lot (L)) to make a proper, but not exactly rational linear wafer start.




Another object of this invention is to provide a method for performing the task of re-scheduling and follow only the Product Control (PC) original of the customer driven Master Production Schedule (MPS).




Still another object of this invention to transform the linear wafers start into linear wafer output performance to ensure customer's satisfaction on volume demanding.




A further object of this invention is to ensure the inline equipment in loading balance.




One more object of this invention is to meet the daily linear wafers output by demand (Designed Out) in conformance with the on time delivery orientation of customers.




In accordance with one aspect of this invention, a system and a method are provided for transforming a set of Linear Wafers Starts (LWS) into a set of Linear Wafers Out (LWO) to ensure customer satisfaction by meeting the product quantity (volume) demands made by customers.




In accordance with another aspect of this invention a system and a method are provided for ensuring balance of loading of inline equipment.




In accordance with another aspect of this invention a system and a method are provided for meeting the daily demand (Designed Out) Linear Wafers Out (LWO) by the on time delivery orientation of customers.




In accordance with this invention use is made of the Due_Date, the link with products, and theoretical process time to make an exact re-scheduling automatically to ensure a linear wafer output.




In accordance with this invention a method and/or system for performing dynamic re-scheduling of priorities of work-in-process in a fabrication plant for manufacturing of a product is provided. It reads a key stage report for the work-in-process and a master production schedule for the work-in-process from stored data. It generates a master production schedule report from the key stage report and the master production schedule following only Due_Date data for the work-in-process, and generates a work-in-process distribution matrix for integrating the master production schedule report with work-in-process quantity data within a deliverable cycle time; allocates selected lots from the work-in-process distribution matrix using a snake pattern method to allocate the selected lots from the matrix, and changes the due date for the selected lots of the work-in-process selected by the snake pattern method. It generates a final re-scheduling table for the work-in-process including the selected lots, where











X
=
1

,

Y
=
1




X
=
n

,

Y
=
3





MPSR


(



Due



Date






(
X
)


,

CT


(
Y
)



)



=

Designed





Out











CT=Cycle Time




X=1, 2, 3 . . . m




Y=1, 2, 3 . . . p




where m and p are positive integers,




It uses the Due_Date data in allocating the selected lots. The method/system uses a link with products in allocating the selected lots and uses theoretical process time to make an exact re-scheduling automatically to ensure linear wafer output performance in allocating the selected lots when forming the master production schedule fitting work-in-process in the key stage report to meet requirements of the master production schedule.















GLOSSARY
























Cycle Time




(CT)) Time to go from beginning to end of FAB.






Due_Date




(DD) Scheduled Due Date from MPS, i.e. the date when







processing of a lot must be finished for an order placed







on the MPS.






FAB




Fabrication plant.






MPS




Master Production Schedule.






Required_Date




(RD) Date when lot must be finished out according to the







start date and the average cycle time data of the past.






WIP




Work in Process.





















BRIEF DESCRIPTION OF THE DRAWINGS




The foregoing and other aspects and advantages of this invention are explained and described below with reference to the accompanying drawings, in which:





FIG. 1

is a chart which shows how data is combined to generate a Master Production Schedule Report (MPSR) through integration of a Key Stage Report (KSR) and a Master Production Schedule (MPS).





FIG. 2

is a flow chart of a computer program showing the steps of a method of operation of a production control system in accordance with the method and system of this invention.





FIG. 3

shows a manufacturing plant which includes a central computer system and a fabrication plant with a shop floor where products, such as semiconductor chips, are being manufactured and a computer system for allocating fabrication plant resources in accordance with this invention.





FIG. 4

is a chart showing a portion of a KSR (Key Stage Report) which is a report on the process flow of the fabrication plant (FAB).





FIG. 5

is a chart showing a portion of a MPS (Master Production Schedule) which is a customer driven table reflecting the schedule demands of customers.





FIG. 6

is a chart showing a portion of a MPSR (Master Production Schedule Report) which integrates the customer driven MPS table and the KSR.





FIG. 7

is a chart showing an example of a Work in Process (WIP) MPSR matrix.





FIG. 8

is a chart showing an enlarged portion of the chart of

FIG. 7

with wafers selected from the MPSR matrix shown in

FIG. 7

by scanning adjacent columns of wafers with snake patterns.





FIG. 9

shows the resultant New Master Production Schedule (NMPS) produced by the system and method of this invention.











DESCRIPTION OF THE PREFERRED EMBODIMENT




This is a method for performing dynamic re-scheduling of a fabrication plant. This method defines the due date of a lot Ln (where n is a positive integer) without changing the required date of the lot Ln whose due date is being defined.




Generate a Master Production Schedule Report





FIG. 1

is a chart which shows how data is combined to generate a Master Production Schedule Report (MPSR)


35


through integration of a Key Stage Report (KSR)


20


and a Master Production Schedule (MPS)


31


and without concern about the Required_Date (RD), but by following only the Due_Date (DD) data. Note that the Master Production Schedule (MPS) is shown also in FIG.


5


.





FIG. 2

is a flow chart of a computer program showing the steps of a method of operation of a production control system in accordance with the method and system of this invention. The flow chart starts with step


40


in FIG.


2


. Next step


41


causes the system to read the KSR report


20


(shown in FIG.


1


and

FIG. 4

) in FIG.


2


. Simultaneously step


42


causes the system to read the MPS


31


(shown in FIG.


1


and FIG.


5


). Steps


41


and


42


lead to step


43


in

FIG. 2

which causes the system to generate the Master Production Schedule Report (MPSR)


35


(shown in FIG.


1


and FIG.


6


).




System Configuration





FIG. 3

shows a manufacturing plant


50


which includes a central computer system


60


and a fabrication plant


90


with a shop floor


87


where products, such as semiconductor chips, are being manufactured and a computer system


70


for allocating fabrication plant resources in accordance with this invention.




The computer program of

FIG. 2

in accordance with this invention is preferably resident in a site in the fabrication plant computer system


70


which is preferably connected, as shown in

FIG. 3

, as a part of the overall computer system with the central computer system


60


, which is an alternative site for the computer program of FIG.


2


.




Referring again to

FIG. 3

, the computer system


70


operates as an integral part of the fabrication plant


90


and so it is shown located within the plant


90


, but it may be located elsewhere, as will be obvious to those skilled in the art and it can be a portion of an overall consolidated system incorporating the central computer system


60


and can operate independently as a matter of choice.




The central computer system


60


shown in

FIG. 3

comprises a CPU (Central Processing Unit)


61


, a terminal


67


with a monitor


62


and a keyboard


63


connected to the CPU


61


for receiving/sending data respectively from/to the CPU


61


. A RAM (Random Access Memory)


65


and a DASD


64


associated with the CPU


61


are shown connected for bidirectional communication of data to and from CPU


61


.




Lines


76


,


176


and


276


provide for interconnections between the CPU


61


of system


60


to the CPU


71


of the fabrication plant computer system


70


. Line


176


connects between lines


76


and


276


at the interfaces of computer


60


and a factory control computer system


70


respectively.




The factory control computer system


70


comprises a CPU


71


, a terminal


77


with monitor


72


and keyboard


73


connected to the CPU


71


for receiving/sending data respectively from/to the CPU


71


. A random access memory


75


and a DASD


74


associated with the CPU


71


are shown connected for bidirectional communication of data to and from CPU


71


. Line


86


connects from CPU


71


to line


186


connects through the factory control computer


70


interface to the shop floor system


87


.




The system


50


includes the data defining the Master Production Schedule (MPS) and the Key Stage Report (KSR) for the plant


90


stored in one of the DASD unit


64


, DASD unit


74


RAM


65


or RAM


75


, as desired, in a conventional manner, as will be well understood by those skilled in the art.




Process Steps




Referring again to

FIG. 2

, a flow chart shows the method of this invention of employing a data processing system to resolve the differences between the Key Stage Report (KSR)


20


and a Master Production Schedule (MPS)


31


. The data processing system of

FIG. 3

performs functions defined by the process control steps shown in FIG.


2


.




As stated above, the method of this invention starts in step


40


when the system


50


in

FIG. 3

initiates the steps of reading the Key Stage Report (KSR)


20


in step


41


, simultaneously with the reading of the Master Production Schedule (MPS)


31


in step


42


from DASD unit


64


, RAM


65


, DASD unit


74


, and/or RAM


75


.





FIG. 4

is a chart showing a portion of a KSR (Key Stage Report) which is a report on the process flow of the fabrication plant (FAB). The KSR (Key Stage Report)


20


of

FIGS. 1 and 4

is read by the program of

FIG. 2

in step


41


, is a report on the process flow of the fabrication plant (FAB). The KSR


20


includes the data for the processing tools on the shop floor


87


in

FIG. 3

which include “Stage 1”


21


, “Stage 2”


22


, “Stage 3”


23


, . . . and the “QC-insp stage”


27


. Stage


27


performs Quality Control (QC) and inspection (insp). In the KSR in

FIG. 1

, the first wafer “W1”


24


is located for processing by “Stage 1”


21


. The second wafer “W2”


25


is located for processing by “Stage 2”


22


. The third wafer “W3”


26


is located for processing by “Stage 3”


23


. The “QC-insp stage”


27


is the last stage on the floor of the FAB which is where wafers WA


28


(product A) and WB


29


(product B) are located.


















Definitions for KSR:













A = Product A







B = Product B







W1 = Wafer







W2 = Wafer







W3 = Wafer







WA = Wafer







WB = Wafer







S1a = Wafer Lot 1a







S2a = Wafer Lot 2a







S3a = Wafer Lot 3a







S4a = Wafer Lot 4a







S5a = Wafer Lot 5a







S1b = Wafer Lot 1b







S2b = Wafer Lot 2b







S3b = Wafer Lot 3b







S4b = Wafer Lot 4b







S5b = Wafer Lot 5b
















FIG. 5

is a chart showing a portion of a MPS (Master Production Schedule) which is a customer driven table reflecting the schedule demands of customers. The MPS (Master Production Schedule)


31


in

FIGS. 1 and 5

is a table with block


33


A for wafer lots S


1




a


, S


2




a


, S


3




a


, S


4




a


, and S


5




a


, etc. for product A and with block


33


B for wafer lots S


1




b


, S


2




b


, S


3




b


, S


4




b


, and S


5




b


, etc. for product B, for the various dates including date


1


, date


2


, date


3


, date


4


, date


5


. . . date


31


, as described below.




For product A the schedule for ordered lots in block


33


A includes wafer lots S


1




a


, S


2




a


, S


3




a


, S


4




a


, and S


5




a


scheduled for the dates of date


1


, date


2


, date


3


, date


4


, and date


5


, respectively.




For product B the schedule for ordered lots in block


33


B includes lots S


1




b


, S


2




b


, S


3




b


, S


4




b


, and S


5




b


scheduled for the dates of date


1


, date


2


, date


3


, date


4


, and date


5


, respectively.




The MPS table


31


in

FIGS. 1 and 5

shows an example of the first five days of a monthly production schedule for products A and B. The MPS table, as shown, suggests the inclusion of data for a thirty-one (31) day month.




Generation of Master Production Schedule Report





FIG. 6

is a chart showing a portion of a MPSR (Master Production Schedule Report) which integrates the customer driven MPS table and the KSR.




In step


43


of

FIG. 2

, the system


70


generates a Master Production Schedule Report (MPSR)


35


in

FIGS. 1 and 6

by integration of the KSR report from step


41


of

FIG. 2

with the MPS report from step


42


of

FIG. 2

following only the Due_Date in making the sequence determinations.




In accordance with this invention, the lots are fit into a sequence selected from the KSR (Key Stage Report) to meet the Master Production Schedule Report (MPSR) needs producing the MPSR


35


in

FIGS. 1 and 6

As it turns out in this example, in report


35


in

FIGS. 1 and 6

, for product A in box


36


, the lot S


2




a


at Date


1


is first and the lot S


4




a


at Date


5


is last. In the case of product B in box


37


, the lot S


4




b


at Date


1


is first and the lot S


3




b


at Date


5


is last.




From report


35


line


38


leads to block


39


which includes as follows:




Date


1


,


2


. . . ; Required Date; Date


1


,


2


. . . ; Due_Date




Use Matrix to Integrate MPSR with Wafers Quantity within Deliverable Cycle Time




In step


44


in

FIG. 2

, the system


70


obtains WIP quantity data.




In step


45


, the system


70


generates an MPSR matrix seen in

FIG. 7

to integrate the master production schedule report (MPSR) with the quantity of wafers from the WIP quantity data within deliverable Cycle Time (CTn where n is a positive integer).

FIG. 7

shows an example of a Work in Process (WIP) MPSR matrix, as follows:




S


2




a




1


, S


1




a




1


, S


4




a




1


, S


4




a




2


and S


2




b




2


for wafer count CT


1






S


4




b




1


, S


2




a




2


, S


1




a




2


, S


1




b




1


and S


2




b




1


for wafer count CT


2






S


4




b




2


, S


5




b




1


, S


5




b




2


, S


3




a




2


and S


3




b




2


for wafer count CT


3






S


1




b




2


, S


3




b




1


, S


3




a




1


, S


5




a




1


and S


5




a




2


for wafer count CT


4






EQUATION
















X
=
1

,

Y
=
1




X
=
n

,

Y
=
3





MPSR


(



Due



Date






(
X
)


,

CT


(
Y
)



)



=

Designed





Out











Cycle Time (CT)=Time to go from beginning to end of FAB




X=1, 2, 3 . . . m




Y=1, 2, 3 . . . p




where m and p are positive integers.




Select Wafers from Above WIP Distribution by Scanning the Matrix with Snake Patterns




Referring to

FIG. 8

, in step


46


in

FIG. 2

, wafers are selected from the MPSR matrix shown in

FIG. 7

by scanning adjacent columns of wafers with a pair of snake patterns illustrating a set of such patterns which is required to scan the entire matrix of FIG.


7


. The first snake pattern P


1


proceeds along an initial column in one direction but before completing a scan of the column jumps over to the adjacent column and scans a portion the second column as well. The second snake pattern scan P


2


employed is complementary to the first snake pattern. Accordingly the pattern is different, but it is juxtaposed with the initial scan.




While the scans are shown to be juxtaposed, it is possible to interleave scans leaving gaps between scans.




A first snake pattern P


1


goes down column


1


through the first three wafers and then goes up to the top of column


2


and processes the first three wafers in column


2


where it stops.




The second snake pattern P


2


goes from the bottom of column


1


through the bottom of column


2


to the top of column


3


and processes the first three wafers in column


3


.




The snake patterns P


1


and P


2


seen in

FIG. 8

are examples and many other snake patterns can be used.




The use of a sequence of snake patterns continues until selection of all of the WIP in the manufacturing process is completed.




Change Due Dates of Selected Wafers




In step


47


of

FIG. 2

, the Due_Dates of the wafers selected in step


46


are changed in the mean time.




Provide Final Re-scheduling Table




In step


48


of

FIG. 2

, the final re-scheduling table of the New Master Production Schedule (NMPS) is provided as shown in

FIG. 9

where the rescheduled “R” wafers replace the scheduled “S” wafers from the MPS of FIG.


5


. Again the table suggests the inclusion of data for the use with a thirty-one (31) day month.





FIG. 9

shows the resultant New Master Production Schedule (NMPS) produced by the system and method of this invention with the new due_dates from step


47


.




The resultant quantities will meet the Master Production Schedule (MPS) requirements, but lots from the Key Stage Report (KSR) will be different from the original values.




After step


48


the method of this invention ends in step


49


.




As is stated above in step


43


, use is made of the Due_Date.




In accordance with this invention use is made of the Due_Date, the link with products, and theoretical process time to make an exact re-scheduling automatically to ensure a linear wafer output.




This is a method for re-scheduling dynamically to define the Due_Date of a lot without changing the required date of the lot.




While this invention has been described in terms of the above specific embodiment(s), those skilled in the art will recognize that the invention can be practiced with modifications within the spirit and scope of the appended claims, i.e. that changes can be made in form and detail, without departing from the spirit and scope of the invention. Accordingly all such changes come within the purview of the present invention and the invention encompasses the subject matter of the claims which follow.




Below is found Table I which shows an example of a Key Stage Report.












TABLE I











KEY STAGE REPORT (KSR)


































Cur






Gen-




Sin-














Cur




Held




Run




Cum




Cur




Tar-





0.6




us




gle




0.6




.8/1.0




DP




SAC






0.6






Stage ID




WIP




WIP




WIP




WIP




Move




get




BPTEOS




WIP




WIP




Metal




SM




WIP




WIP




WIP




TM4457




TM5334




TLM































WAF-




12




12




0




21994




1002




1000




12




12




12




0




0




0




0




0




0




0




0






START






PAD-




72




48




0




21982




312




240






72




24





72




0






OX-1






SIN-1-




96




0




96




21910




312




288






96




96





96




0






DEP






NWELL-




408




0




145




21814




750




860




288




192




288




24




24




216




0




120




0




0




0






PHO






SIN-1-




0




0




0




21406




0




0






0






0






PHO






P-WL-1-




0




0




0




21406




0




0







0





0






PHO






SIN-1-




48




0




0




21406




312




180






48




0





48




0






ETCH






N-WL-1-




156




12




96




21358




606




320




12




84




156




96




72




72




0





0




0




0






IMP






P-WL-1-




0




0




0




21202




0




0







0





0






IMP






WELL-




96




0




96




21202




144




240






96




24





96




0






OX






SIN-1-RM




120




0




120




21106




24




240






120




72





120




0






N-WL-2-




0




0




0




20986




324




188




0






0





0




0




0






IMP






N-WL-




168




0




120




20986




324




220




168






0





168




0




168






DRIV






PWELL-




0




0




0




20818




534




560




0




0




0




0





0




0





0




0




0






PHO






P-WL-2-




48




0




0




20818




510




600




24




24




48




0




0




24




0





0




0




24






IMP






P-WL-




0




0




0




20770




0




0






0




0




0




0




0






DRIV






WELL-




456




0




420




20770




270




380




432




432




456




0




0




24




0





0




0




300






DRIV






PAD-




222




0




126




20314




516




420




222




126




126




0




0




96




6




96




48




0




48






OX-2






SIN-2-




84




0




84




20092




672




550




84




0




0




0




0




84




0




84




0




0




0






DEP






SIN-2-




253




58




15




20008




775




860




195




99




135




0




0




154




24




96




0




0




0






PHO






SIN-2-




179




0




0




19755




789




880




155




59




83




0




0




120




0




96




0




0




24






ETCH






N- FLD




96




0




48




19576




504




36




96








96





96






IMP






P-





FLD




120




0




72




19480




969




960




120




0




0




0




0




120




0




120




0




0




0






PHO






P-





FLD




24




0




0




19360




1088




920




24




0




0




0




0




24




0




24




0




0




0






IMP






DEEP1-




188




0




48




19336




924




720




188




44




44




0




0




144




0




144




0




0




20






IMP






DEEP-2-




0




0




0




19148




0




3




0





0




0






0






PHO






DEEP-2-




0




0




0




19148




0




3




0





0




0






0






IMP






FIELD-




391




0




343




19148




1313




1100




343




151




175




24




24




240




24




216




0




0




48






OX






SIN-2-RM




324




0




120




18757




989




920




204




276




324




72




72




48




24




0




0




0




168






SAC-




24




0




0




18433




48




3




0




24




24




24




24





0






OX-1






CHAN1-




0




0




0




18409




0




0




0




0








0






PHO






CHAN1-




0




0




0




18409




0




0




0




0








0






IMP






GATE-




48




0




0




18409




48




51




0




48




48




48




48





0






OX-1






POLY-1-




0




0




0




18361




0




3




0




0




0




0






0






DEP






SIN-3-




0




0




0




18361




48




27




0





0




0






0






DEP






BKPO-




0




0




0




18361




0




0




0




0








0






LY1-RM






POLY1-




0




0




0




18361




0




0




0




0








0






DOPE






POLY-1-




0




0




0




18361




0




0




0




0








0






OX






POLY-1-




48




0




0




18361




64




27




48




0




48




48






48






PHO






PO-SN-




42




0




0




18313




22




27




42





42




42






42






ETCH






POLY-1-




0




0




0




18271




22




27




0





0




0






0






IMP






POLY1-




0




0




0




18271




0




0




0




0








0






ETCH






BAR1-




0




0




0




18271




0




0




0




0








0






IMP






CELL-1-




22




0




0




18271




0




27




22





22




22






22






IMP






CELL-2-




0




0




0




18249




0




27




0





0




0






0






IMP






SAC-




209




0




137




18249




828




782




161




161




209




0





48




24




0




0




0




113






OX-2






VT1 P




0




0




0




18040




0




0









0






IMP0






POLY1-




0




0




0




18040




2




27




0




0




0




0






0











OX






SIN-3-RM




0




0




0




18040




2




27




0





0




0






0






CA-N-




0




0




0




18040




0




0






0






0






PHO






PO-I-




7




7




0




18040




0




8




7





7




7






7






ETCH






CA-N-




0




0




0




18033




0




0






0






0






IMP






BR-S/D-




72




24




0




18033




144




172




0




72




72




72




72






PHO






BR-S/D-




24




0




0




17961




120




168




0




24




24




24




24






IMP






CPT-




24




0




0




17937




144




140




0




24




24




24




24






PHO






CPT-IMP




120




0




72




17913




48




96




0




120




120




120




120






XX-PHO




82




0




45




17793




110




180




64




64




76




18





18




64






XX-N-




63




0




0




17711




35




120




51




51




63




12





12




51






IMP






VT1 P




228




0




72




17648




743




780




96




96




168




0




0




132




72





0




0




0






IMP1






VT1-




0




0




0




17420




288




220




0








0





0











PHO














Below is found Table II which shows an example of a Master Production Schedule.












TABLE II











MASTER PRODUCTION SCHEDULE (MPS)






Date1, 2 . . . : Required Date; Date1, 2 . . . Due Date






SUBJECT: FAB-2A OUTPUT SCHEDULED VS. ACTUAL WEEKLY PERFORMANCE FOR - AUGUST 1997
















PROD





SCHEDULE




ACTUAL




PERFORMANCE




MTD





























RUN***




C/P




PKG





01-07




08-14




15-21




22-31




MTD




01-07




08-14




15-21




22-31




MTD




01-07




08-14




15-21




MTD




DELAY






























DEVICE




MPS




*




#




ESTI




WK732




WK133




WK734




WK735




TOTAL




WK732




WK733




WK734




WK735




TOTAL




WK732




WK733




WK734




TOTAL




Q'TY

































TM1294




216






216




48




72




0




96




216




72




24




0




0




96




150%




 80%




 80%




 44%




120






TM4635




24






24




0




0




24




0




24




0




0




0




0




0






 0%




 0%




24






TM3779




12






12




0




0




12




0




12




0




6




0




0




6






 50%




 50%




6






TM4142




24






24




0




0




12




12




24




6




0




0




0




6






 50%




 25%




18






TM4352




9






9




0




0




9




0




9




0




0




8




0




8






 89%




 89%




1






TM5672




12






12




0




0




12




0




12




0




6




0




0




6






 50%




 50%




6






TM5607




6






6




0




0




6




0




6




0




3




0




0




3






 50%




 50%




3






TM1428




48






48




0




0




0




48




48




0




0




0




0




0







 0%




48






TM0975




24






24




0




0




0




24




24




0




0




0




0




0







 0%




24






TM1175




240






240




72




0




0




168




240




72




0




0




71




143




100%




100%




100%




 60%




97






TM0794




12




*





12




0




0




0




12




12




0




0




0




0




0







 0%




12






TM1977




168




*





168




0




0




0




168




168




0




0




144




0




144







 86%




24






TM2290




36






36




0




0




0




36




36




0




0




24




0




24







 67%




12






TM2461




24






24




0




0




0




24




24




0




0




0




0




0







 0%




24






TM5609




6






6




0




6




0




0




6




0




5




0




0




5





 83%




 83%




 83%




1






TM4849




456






456




0




0




0




456




456




0




0




0




354




354







 78%




102






TM4940




600






600




0




0




336




264




600




0




0




310




95




405






 92%




 68%




195






TM3306




120






120




0




0




120




0




120




0




0




70




2




72






 58%




 60%




48






TM3023




36




*





36




0




0




0




36




36




0




0




0




24




24







 67%




12






TM4075




2153




*




#




2153




357




728




456




612




2153




260




871




237




473




1841




 73%




104%




 89%




 86%




312






TM2669




30




*




#




30




0




0




12




18




30




0




0




0




18




18






 0%




 60%




12






TM5678




6






6




0




0




0




6




6




0




3




0




0




3







 50%




3






TM5654




12






12




0




12




0




0




12




0




6




0




0




6





 50%




 50%




 50%




6






TM5683




12






12




0




0




12




0




12




0




0




0




4




4






 0%




 33%




8






TM3546




144




*




#




144




0




0




24




120




144




0




0




8




24




32






 33%




 22%




112






TM4379




48






48




24




0




0




24




48




24




0




0




0




24




100%




100%




100%




 50%




24






TM1932




158




*




#




158




0




62




0




96




158




59




2




0




79




140





 98%




 98%




 89%




18






TM5676




12






12




0




0




12




0




12




0




6




0




0




6






 50%




 50%




6






TM5682




12






12




0




0




12




0




12




0




0




6




0




6






 50%




 50%




6






TM2403




91






91




0




19




0




72




91




0




19




0




0




19





100%




100%




 21%




72






TM3429




72






72




0




0




0




72




72




0




0




0




0




0







 0%




72






TM4375




96






96




0




48




0




48




96




0




42




0




0




42





 88%




 88%




 44%




54






TM4634




406






406




142




96




0




168




406




118




120




0




24




262




 83%




100%




100%




 65%




144






TM2691




404






404




308




96




0




0




404




334




24




0




0




358




108%




 89%




 89%




 89%




46






TM2726




120






120




0




0




120




0




120




0




0




0




99




99






 0%




 83%




21






TM2737




2831






2831




359




792




816




864




2831




359




310




574




906




2149




100%




 58%




 63%




 76%




682






TM2746




288






288




72




0




0




216




288




72




0




0




115




187




100%




100%




100%




 65%




101






TM3161




24






24




0




0




0




24




24




0




0




0




0




0







 0%




24






TM3162




335




*





335




0




167




48




120




335




0




41




72




40




153





 25%




 53%




 46%




182






TM2913




264




*





264




0




48




48




168




264




24




24




24




159




231





100%




 75%




 88%




33






TM3292




1054




*





1054




286




192




240




336




1054




259




190




169




299




917




 91%




 94%




 86%




 87%




137






TM3810




167






167




47




0




96




24




167




23




24




72




24




143




 49%




100%




 83%




 86%




24






TM4243




216






216




24




24




0




168




216




48




120




0




−24




192




200%




350%




350%




 89%




24






TM4294




48






48




0




0




0




48




48




0




0




0




0




0







 0%




48






TM5017




36






36




6




0




30




0




36




6




6




0




0




12




100%




200%




 33%




 33%




24






TM5046




105






105




9




0




0




96




105




9




0




21




50




80




100%




100%




333%




 76%




25






TM5095




72






72




0




0




0




72




72




0




0




0




0




0







 0%




72






TM5106




72






72




0




0




0




72




72




0




6




5




0




11







 15%




61






TM5679




16






16




0




16




0




0




16




0




4




0




0




4





 25%




 25%




 25%




12






TM2665




96




*





96




0




0




24




72




96




0




24




0




0




24






100%




 25%




72






TM4613




156






156




0




156




0




0




156




0




120




3




0




123





 77%




 79%




 79%




33






TM4615




240






240




168




72




0




0




240




120




71




0




0




191




 71%




 80%




 80%




 80%




49






TM4655




6






6




6




0




0




0




6




3




0




0




0




3




 50%




 50%




 50%




 50%




3






TM2514




120




*





120




120




0




0




0




120




71




0




0




0




71




 59%




 59%




 59%




 59%




49






ENG




200






200




0




50




0




150




200




42




17




8




85




152





118%




134%




 76%




48






TOTAL




42000






42000




9826




9171




9614




13389




42000




10008




9063




9790




13188




42049




102%




100%




101%




100%




192

















IN TIME OUTPUT PERFORMANCE




42000





37808





 90%













Claims
  • 1. A method for performing dynamic re-scheduling of priorities of work-in-process in a fabrication plant for manufacturing of a product comprising:reading a key stage report for said work-in-process and a master production schedule for said work-in-process from stored data, generating a master production schedule report from said key stage report and said master production schedule following only Due_Date data for said work-in-process, generating a work-in-process distribution matrix for integrating said master production schedule report with work-in-process quantity data within a deliverable cycle time, allocating selected lots from said work-in-process distribution matrix using a snake pattern method to allocate said selected lots from said matrix, change the due date for said selected lots of said work-in-process selected by said snake pattern method, and generating a final re-scheduling table for said work-in-process including said selected lots.
  • 2. A method in accordance with claim 1 including:using said Due_Date data in allocating said selected lots.
  • 3. A method in accordance with claim 1 including:using a link with products in allocating said selected lots.
  • 4. A method in accordance with claim 1 including:using theoretical process time to make an exact re-scheduling automatically to ensure linear wafer output performance in allocating said selected lots.
  • 5. A method in accordance with claim 1 including:when forming said master production schedule fitting work-in-process in said key stage report to meet requirements of said master production schedule.
  • 6. A method in accordance with claim 1 including:using said Due_Date data in allocating said selected lots, using a link with products in allocating said selected lots, using theoretical process time to make an exact re-scheduling automatically to ensure linear wafer output performance in allocating said selected lots, and fitting work-in-process in said key stage report to meet requirements of said master production schedule when forming said master production schedule.
  • 7. A method in accordance with claim 1 including determining: ∑X=1,Y=1X=n,Y=3⁢MPSR⁡(Due—⁢Date⁢ ⁢(X),CT⁡(Y))=Designed⁢ ⁢OutCT=Cycle Time X=1, 2, 3 . . . m Y=1, 2, 3 . . . p where m and p are positive integers and MPSR=Master Production Schedule Report.
  • 8. A method in accordance with claim 7 including:using the Due_Date in allocating said selected lots.
  • 9. A method in accordance with claim 7 including:using a link with products in allocating said selected lots.
  • 10. A method in accordance with claim 7 including:using theoretical process time to make an exact re-scheduling automatically to ensure linear wafer output performance in allocating said selected lots.
  • 11. A method in accordance with claim 7 including:fitting work-in-process in said key stage report to meet requirements of said master production schedule when forming said master production schedule.
  • 12. A method for performing dynamic re-scheduling of priorities of work-in-process in a fabrication plant for manufacturing of a product comprising:reading a key stage report for said work-in-process and a master production schedule for said work-in-process from stored data, generating a master production schedule report from said key stage report and said master production schedule following only Due_Date data for said work-in-process, generating a work-in-process distribution matrix for integrating said master production schedule report with work-in-process quantity data within a deliverable cycle time, allocating selected lots from said work-in-process distribution matrix using a snake pattern method to allocate said selected lots from said matrix, changing the due date for said selected lots of said work-in-process selected by said snake pattern method, and generating a final re-scheduling table for said work-in-process including said selected lots, where ∑X=1,Y=1X=n,Y=3⁢MPSR⁡(Due—⁢Date⁢ ⁢(X),CT⁡(Y))=Designed⁢ ⁢OutCT=Cycle Time X=1, 2, 3 . . . m Y=1, 2, 3 . . . p where m and p are positive integers and MPSR=Master Production Schedule Report, using said Due_Date data in allocating said selected lots, using a link with products in allocating said selected lots, using theoretical process time to make an exact re-scheduling automatically to ensure linear wafer output performance in allocating said selected lots, and fitting work-in-process in said key stage report to meet requirements of said master production schedule when forming said master production schedule.
  • 13. A system for performing dynamic re-scheduling of priorities of work-in-process (WIP) in a fabrication plant for manufacturing of a product comprising:key stage report means for performing the step of reading a key stage report for said work-in-process and a master production schedule (MPS) for said work-in-process from stored data, MPS schedule report means for performing the step of generating a master production schedule report from said key stage report and said master production schedule following only Due_Date data for said work-in-process, WIP distribution matrix means for performing the step of generating a work-in-process distribution matrix for integrating said master production schedule report with work-in-process quantity data within a deliverable cycle time, allocation means for performing the step of allocating selected lots from said work-in-process distribution matrix using a snake pattern method to allocate said selected lots from said matrix, rescheduling means for performing the step of changing the due date for said selected lots of said work-in-process selected by said snake pattern method, and re-scheduling table means for performing the step of generating a final re-scheduling table for said work-in-process including said selected lots.
  • 14. A system in accordance with claim 13 including Due_Date data means for performing the step of using said Due_Date data in allocating said selected lots.
  • 15. A system in accordance with claim 13 including link means for performing the step of using a link with products in allocating said selected lots.
  • 16. A system in accordance with claim 13 including theoretical process time means for performing the step of using theoretical process time to make an exact re-scheduling automatically to ensure linear wafer output performance in allocating said selected lots.
  • 17. A system in accordance with claim 13 including fitting means for performing the step of fitting work-in-process in said key stage report to meet requirements of said master production schedule when forming said master production schedule.
  • 18. A system in accordance with claim 13 including:Due_Date data means for performing the step of using said Due_Date data in allocating said selected lots, link means for performing the step of using a link with products in allocating said selected lots, theoretical process time means for performing the step of using theoretical process time to make an exact re-scheduling automatically to ensure linear wafer output performance in allocating said selected lots, and fitting means for performing the step of fitting work-in-process in said key stage report to meet requirements of said master production schedule when forming said master production schedule.
  • 19. A system in accordance with claim 13 including means for performing the step of determining: ∑X=1,Y=1X=n,Y=3⁢MPSR⁢ ⁢(Due—⁢Date⁢ ⁢(X),CT⁡(Y))=Designed⁢ ⁢OutCT=Cycle⁢ ⁢TimeX=1,2,3⁢ ⁢…⁢ ⁢mY=1,2,3⁢ ⁢…⁢ ⁢pwhere m and p are positive integers and MPSR=Master Production Schedule Report.
  • 20. A system in accordance with claim 19 including Due_Date means for performing the step of using the Due_Date in allocating said selected lots.
  • 21. A system in accordance with claim 19 including link means for performing the step of using a link with products in allocating said selected lots.
  • 22. A system in accordance with claim 19 including theoretical process time means for performing the step of using theoretical process time to make an exact re-scheduling automatically to ensure linear wafer output performance in allocating said selected lots.
  • 23. A system in accordance with claim 19 including fitting means for performing the step of fitting work-in-process in said key stage report to meet requirements of said master production schedule when forming said master production schedule.
  • 24. A system for performing dynamic re-scheduling of priorities of work-in-process in a fabrication plant for manufacturing of a product comprising:reading means for performing the step of reading a key stage report for said work-in-process and a master production schedule (MPS) for said work-in-process from stored data, MPS report means for performing the step of generating a master production schedule report from said key stage report and said master production schedule following only Due_Date data for said work-in-process, matrix means for performing the step of generating a work-in-process distribution matrix for integrating said master production schedule report with work-in-process quantity data within a deliverable cycle time, allocation means for performing the step of allocating selected lots from said work-in-process distribution matrix using a snake pattern method to allocate said selected lots from said matrix, change means for performing the step of changing the due date for said selected lots of said work-in-process selected by said snake pattern method, and re-scheduling means for performing the step of generating a final re-scheduling table for said work-in-process including said selected lots, where ∑X=1,Y=1X=n,Y=3⁢MPSR⁢ ⁢(Due—⁢Date⁢ ⁢(X),CT⁡(Y))=Designed⁢ ⁢OutCT=Cycle⁢ ⁢TimeX=1,2,3⁢ ⁢…⁢ ⁢mY=1,2,3⁢ ⁢…⁢ ⁢pwhere m and p are positive integers and MPSR=Master Production Schedule Report. Due_Date data means for performing the step of using said Due_Date data in allocating said selected lots, link means for performing the step of using a link with products in allocating said selected lots, theoretical process time means for performing the step of using theoretical process time to make an exact re-scheduling automatically to ensure linear wafer output performance in allocating said selected lots, and fitting means for performing the step of fitting work-in-process in said key stage report to meet requirements of said master production schedule when forming said revised master production schedule.
US Referenced Citations (3)
Number Name Date Kind
5546326 Tai et al. Aug 1996 A
5612886 Weng Mar 1997 A
6088626 Lilly et al. Jul 2000 A
Non-Patent Literature Citations (3)
Entry
Liu et al., “A Methodology for Improving On-Time Delivery and Load Leveling Starts,” IEEE/Semi Advanced Semiconductor Manufacturing Conference, pp. 95-100 (1995).
Murty et al., “Global Planning at Harris Semiconductor, 1995 International Symposium on Semiconductor Manufacturing”, pp. 18-23.
Hoitomt et al., “Scheduling a Batch Processing Facility”, Proceedings of the 1992 IEEE International Conference of Robotics and Automation, Nice France, (1992) pp. 1167-1172.