⚙ Controls
1 Set production batch and transfer batch sizes
2 Notice: smaller transfer batch = earlier M2 start
3 Add SMED to cut setups and see profit climb
💼 Interview Tip
Goldratt Rule #7: "The transfer batch may not, and many times should not, be equal to the process batch." Splitting a batch of 1000 into 10 transfers of 100 lets the next station start sooner without changing throughput. This is a key insight of synchronized manufacturing and directly reduces lead time via overlap.
Instructor Notes
- Hold production batch at 40, toggle transfer batch between 40 and 5. Lead time drops dramatically even though throughput is identical.
- Then apply SMED (cut both setups) and notice profit/hr climb because holding cost drops.
- Discuss: when M2 is slower than M1, buffer grows between them. The transfer batch controls how early M2 starts.
📊 System View
M1 Rate
-
➔
Transfer
10u
➔
M2 Rate
-
➔
Demand
12
M1 Rate
-
M2 Rate
-
Throughput
-
Meets Demand?
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Lead Time
-
Avg WIP
-
Revenue/Hr
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Cost/Hr
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Profit/Hr
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