alain prioul june 2010 fixed batch kanban system and lead time control
TRANSCRIPT
Alain Prioul
JUNE 2010
FIXED BATCH KANBAN SYSTEMAND LEAD TIME CONTROL
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FIXED BATCH KANBAN SYSTEM
AND
LEAD TIME CONTROL
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PULL SYSTEM - MIFA
TPACustomer
Process 1
Process 2
PC & L
NO LEAD TIME CONTROL
Process
Stagnation
Purc
hase
d pa
rts
Leveling board
Production Lead Time
F. G.Shopstock
Batch building
Demand : forecast/firm
A B C
ABC
NO CONTROL OF THE FLOW
ABC
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BATCH PRODUCTION
A B C A
Stock A =
Lead time of A
time
TPACustomer
PC & L
Leveling board
Demand : forecast/firm
Batch building
A B C
ABCProcess
1Process
2
Purc
hase
d pa
rts
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FIXED BATCH CONCEPT
A B C A
Fixed ?
Fixed duration Fixed quantity ?
Production Cycle Time of A or B or C
Packaging of A or B or C
Nb of Kb in one lot vary with
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FIXED QUANTITY BATCH : LEAD TIME VARIATION
If production duration of B or C is longer, Lead Time of A is longer. Same for B and C.
Same consequence if tool change time is longer than standard.
A B C ACB A
Lead Time A
Stock A
Stock Shortage A
Batch is longer than standard
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Unleveled Withdrawals
Schedule change
POOR LEVELING ALSO IMPACTS LEAD TIME
A B C A BB A
Lead Time A
PIK
A B C
Shopstock
WK
C
AB
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CAUSES OF LEAD TIME VARIATION
Production time longer than standard
Tool change longer than standard
Unleveled withdrawals
Stagnation of information
Even when we fix the quantity of Kanban in a batch, we do not control the Lead Time
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PRODUCTION PATTERN
A B C A B
Schedule is pre-define
Changeovers are planned
B C A
8h 10h 12h 14h 16h
8h 10h 12h 14h 16h
LEAD TIME IS UNDER CONTROL
A
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PRODUCTION PATTERN
Demand stability
Line reliability
OPR control
Pre-requisites
PIK
A
B
C
A B C A BProduction pattern
A BC
Daily demand
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Production pattern
Good visualization of future changeover
Synchronization with preceding or next process is possible
Strong incentive for beeing lean
Advantages
Becomes difficult when law runners are not predictable
No adaptation to demand variations
Disadvantages
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TO REMEMBER
Fixed batch Kanban system do not ensure systematically stability of Lead Time
Lead Time Control is key to control plant performance
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