Question 1
A JIT manufacturing system has 4 jobs with the following data:
| Job | Processing (min) | Due Date (min) | Early Penalty/min | Late Penalty/min |
|-----|-----------------|----------------|-------------------|------------------|
| Component B | 24 | 63 | 3 | 17 |
| Component A | 24 | 38 | 4 | 10 |
| Component C | 36 | 116 | 2 | 17 |
| Component D | 24 | 70 | 3 | 20 |
Using the Earliest Due Date (EDD) sequencing rule, what is the total penalty incurred?
Step-by-step solution (JIT Penalty Calculation):
1. EDD Sequence: Component A โ Component B โ Component D โ Component C
2. Calculate completion times and penalties:
- Component A: completes at 24, due 38, early by 14 min โ penalty 56
- Component B: completes at 48, due 63, early by 15 min โ penalty 45
- Component D: completes at 72, due 70, late by 2 min โ penalty 40
- Component C: completes at 108, due 116, early by 8 min โ penalty 16
3. Total penalty: 157
Answer: 157 penalty points
Key Strategy: JIT scheduling minimizes total earliness + tardiness penalties, balancing inventory costs and customer satisfaction.
1. EDD Sequence: Component A โ Component B โ Component D โ Component C
2. Calculate completion times and penalties:
- Component A: completes at 24, due 38, early by 14 min โ penalty 56
- Component B: completes at 48, due 63, early by 15 min โ penalty 45
- Component D: completes at 72, due 70, late by 2 min โ penalty 40
- Component C: completes at 108, due 116, early by 8 min โ penalty 16
3. Total penalty: 157
Answer: 157 penalty points
Key Strategy: JIT scheduling minimizes total earliness + tardiness penalties, balancing inventory costs and customer satisfaction.