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 D | 43 | 57 | 5 | 15 |
| Component A | 60 | 139 | 3 | 12 |
| Component C | 51 | 81 | 2 | 18 |
| Component B | 26 | 80 | 5 | 16 |
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 D → Component B → Component C → Component A
2. Calculate completion times and penalties:
- Component D: completes at 43, due 57, early by 14 min → penalty 70
- Component B: completes at 69, due 80, early by 11 min → penalty 55
- Component C: completes at 120, due 81, late by 39 min → penalty 702
- Component A: completes at 180, due 139, late by 41 min → penalty 492
3. Total penalty: 1319
Answer: 1319 penalty points
Key Strategy: JIT scheduling minimizes total earliness + tardiness penalties, balancing inventory costs and customer satisfaction.
1. EDD Sequence: Component D → Component B → Component C → Component A
2. Calculate completion times and penalties:
- Component D: completes at 43, due 57, early by 14 min → penalty 70
- Component B: completes at 69, due 80, early by 11 min → penalty 55
- Component C: completes at 120, due 81, late by 39 min → penalty 702
- Component A: completes at 180, due 139, late by 41 min → penalty 492
3. Total penalty: 1319
Answer: 1319 penalty points
Key Strategy: JIT scheduling minimizes total earliness + tardiness penalties, balancing inventory costs and customer satisfaction.