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Machine Breakdown Recovery: Worksheet 2 - Beginner Practice Machine Breakdown Recovery BEGINNER

Ready to master Machine Breakdown Recovery? This entry level practice worksheet (2/10) presents 20 beginner-level challenges. Focus area: pattern recognition. Learn to solve machine breakdown recovery reasoning questions, handle machine breakdown recovery practice, and perfect machine breakdown recovery for competitive exams with our step-by-step solutions.

📝 Worksheet 2 of 10 • 20 questions • ⏱️ Estimated time: 20 minutes • 🎯 Beginner level

What you'll learn in this worksheet:
Your progress through Machine Breakdown Recovery
Worksheet 2 of 10 (11% complete)

Question 1

A machine needs to process 4 jobs. Processing times: - Job C: 90 minutes - Job D: 68 minutes - Job E: 73 minutes - Job B: 90 minutes The machine breaks down at 105 minutes and takes 43 minutes to repair. Jobs are scheduled using Shortest Processing Time (SPT) first rule. What is the total completion time (makespan) after handling the breakdown?
Step-by-step solution (Breakdown Recovery):

1. Original SPT order: Job D → Job E → Job C → Job B
2. Simulate processing with breakdown:
- Job D: 0 → 68
- Job E: Starts at 68, breakdown at 105 (37 min completed), repair 43 min, resume 36 min → completes at 184
- Job C: 184 → 274
- Job B: 274 → 364

3. Total makespan: 364 minutes
4. Delay caused by breakdown: 43 minutes

Answer: 364 minutes

Key Strategy: Simulate the timeline, account for breakdown during active job processing.

Question 2

A machine needs to process 4 jobs. Processing times: - Job E: 47 minutes - Job A: 38 minutes - Job D: 90 minutes - Job B: 58 minutes The machine breaks down at 75 minutes and takes 39 minutes to repair. Jobs are scheduled using Shortest Processing Time (SPT) first rule. What is the total completion time (makespan) after handling the breakdown?
Step-by-step solution (Breakdown Recovery):

1. Original SPT order: Job A → Job E → Job B → Job D
2. Simulate processing with breakdown:
- Job A: 0 → 38
- Job E: Starts at 38, breakdown at 75 (37 min completed), repair 39 min, resume 10 min → completes at 124
- Job B: 124 → 182
- Job D: 182 → 272

3. Total makespan: 272 minutes
4. Delay caused by breakdown: 39 minutes

Answer: 272 minutes

Key Strategy: Simulate the timeline, account for breakdown during active job processing.

Question 3

A machine needs to process 4 jobs. Processing times: - Job B: 51 minutes - Job C: 82 minutes - Job E: 45 minutes - Job A: 58 minutes The machine breaks down at 113 minutes and takes 18 minutes to repair. Jobs are scheduled using Shortest Processing Time (SPT) first rule. What is the total completion time (makespan) after handling the breakdown?
Step-by-step solution (Breakdown Recovery):

1. Original SPT order: Job E → Job B → Job A → Job C
2. Simulate processing with breakdown:
- Job E: 0 → 45
- Job B: 45 → 96
- Job A: Starts at 96, breakdown at 113 (17 min completed), repair 18 min, resume 41 min → completes at 172
- Job C: 172 → 254

3. Total makespan: 254 minutes
4. Delay caused by breakdown: 18 minutes

Answer: 254 minutes

Key Strategy: Simulate the timeline, account for breakdown during active job processing.

Question 4

A machine needs to process 4 jobs. Processing times: - Job A: 82 minutes - Job D: 90 minutes - Job B: 57 minutes - Job C: 68 minutes The machine breaks down at 88 minutes and takes 25 minutes to repair. Jobs are scheduled using Shortest Processing Time (SPT) first rule. What is the total completion time (makespan) after handling the breakdown?
Step-by-step solution (Breakdown Recovery):

1. Original SPT order: Job B → Job C → Job A → Job D
2. Simulate processing with breakdown:
- Job B: 0 → 57
- Job C: Starts at 57, breakdown at 88 (31 min completed), repair 25 min, resume 37 min → completes at 150
- Job A: 150 → 232
- Job D: 232 → 322

3. Total makespan: 322 minutes
4. Delay caused by breakdown: 25 minutes

Answer: 322 minutes

Key Strategy: Simulate the timeline, account for breakdown during active job processing.

Question 5

A machine needs to process 4 jobs. Processing times: - Job A: 62 minutes - Job C: 63 minutes - Job E: 81 minutes - Job D: 42 minutes The machine breaks down at 101 minutes and takes 37 minutes to repair. Jobs are scheduled using Shortest Processing Time (SPT) first rule. What is the total completion time (makespan) after handling the breakdown?
Step-by-step solution (Breakdown Recovery):

1. Original SPT order: Job D → Job A → Job C → Job E
2. Simulate processing with breakdown:
- Job D: 0 → 42
- Job A: Starts at 42, breakdown at 101 (59 min completed), repair 37 min, resume 3 min → completes at 141
- Job C: 141 → 204
- Job E: 204 → 285

3. Total makespan: 285 minutes
4. Delay caused by breakdown: 37 minutes

Answer: 285 minutes

Key Strategy: Simulate the timeline, account for breakdown during active job processing.

Question 6

A machine needs to process 4 jobs. Processing times: - Job E: 58 minutes - Job A: 75 minutes - Job B: 34 minutes - Job D: 73 minutes The machine breaks down at 110 minutes and takes 21 minutes to repair. Jobs are scheduled using Shortest Processing Time (SPT) first rule. What is the total completion time (makespan) after handling the breakdown?
Step-by-step solution (Breakdown Recovery):

1. Original SPT order: Job B → Job E → Job D → Job A
2. Simulate processing with breakdown:
- Job B: 0 → 34
- Job E: 34 → 92
- Job D: Starts at 92, breakdown at 110 (18 min completed), repair 21 min, resume 55 min → completes at 186
- Job A: 186 → 261

3. Total makespan: 261 minutes
4. Delay caused by breakdown: 21 minutes

Answer: 261 minutes

Key Strategy: Simulate the timeline, account for breakdown during active job processing.

Question 7

A machine needs to process 4 jobs. Processing times: - Job D: 46 minutes - Job B: 61 minutes - Job A: 38 minutes - Job E: 63 minutes The machine breaks down at 81 minutes and takes 23 minutes to repair. Jobs are scheduled using Shortest Processing Time (SPT) first rule. What is the total completion time (makespan) after handling the breakdown?
Step-by-step solution (Breakdown Recovery):

1. Original SPT order: Job A → Job D → Job B → Job E
2. Simulate processing with breakdown:
- Job A: 0 → 38
- Job D: Starts at 38, breakdown at 81 (43 min completed), repair 23 min, resume 3 min → completes at 107
- Job B: 107 → 168
- Job E: 168 → 231

3. Total makespan: 231 minutes
4. Delay caused by breakdown: 23 minutes

Answer: 231 minutes

Key Strategy: Simulate the timeline, account for breakdown during active job processing.

Question 8

A machine needs to process 4 jobs. Processing times: - Job C: 69 minutes - Job B: 50 minutes - Job D: 73 minutes - Job A: 49 minutes The machine breaks down at 104 minutes and takes 29 minutes to repair. Jobs are scheduled using Shortest Processing Time (SPT) first rule. What is the total completion time (makespan) after handling the breakdown?
Step-by-step solution (Breakdown Recovery):

1. Original SPT order: Job A → Job B → Job C → Job D
2. Simulate processing with breakdown:
- Job A: 0 → 49
- Job B: 49 → 99
- Job C: Starts at 99, breakdown at 104 (5 min completed), repair 29 min, resume 64 min → completes at 197
- Job D: 197 → 270

3. Total makespan: 270 minutes
4. Delay caused by breakdown: 29 minutes

Answer: 270 minutes

Key Strategy: Simulate the timeline, account for breakdown during active job processing.

Question 9

A machine needs to process 4 jobs. Processing times: - Job E: 60 minutes - Job C: 71 minutes - Job D: 44 minutes - Job B: 76 minutes The machine breaks down at 66 minutes and takes 33 minutes to repair. Jobs are scheduled using Shortest Processing Time (SPT) first rule. What is the total completion time (makespan) after handling the breakdown?
Step-by-step solution (Breakdown Recovery):

1. Original SPT order: Job D → Job E → Job C → Job B
2. Simulate processing with breakdown:
- Job D: 0 → 44
- Job E: Starts at 44, breakdown at 66 (22 min completed), repair 33 min, resume 38 min → completes at 137
- Job C: 137 → 208
- Job B: 208 → 284

3. Total makespan: 284 minutes
4. Delay caused by breakdown: 33 minutes

Answer: 284 minutes

Key Strategy: Simulate the timeline, account for breakdown during active job processing.

Question 10

A machine needs to process 4 jobs. Processing times: - Job A: 68 minutes - Job D: 80 minutes - Job B: 71 minutes - Job E: 82 minutes The machine breaks down at 66 minutes and takes 23 minutes to repair. Jobs are scheduled using Shortest Processing Time (SPT) first rule. What is the total completion time (makespan) after handling the breakdown?
Step-by-step solution (Breakdown Recovery):

1. Original SPT order: Job A → Job B → Job D → Job E
2. Simulate processing with breakdown:
- Job A: Starts at 0, breakdown at 66 (66 min completed), repair 23 min, resume 2 min → completes at 91
- Job B: 91 → 162
- Job D: 162 → 242
- Job E: 242 → 324

3. Total makespan: 324 minutes
4. Delay caused by breakdown: 23 minutes

Answer: 324 minutes

Key Strategy: Simulate the timeline, account for breakdown during active job processing.

Question 11

A machine needs to process 4 jobs. Processing times: - Job A: 53 minutes - Job B: 90 minutes - Job D: 40 minutes - Job C: 87 minutes The machine breaks down at 91 minutes and takes 31 minutes to repair. Jobs are scheduled using Shortest Processing Time (SPT) first rule. What is the total completion time (makespan) after handling the breakdown?
Step-by-step solution (Breakdown Recovery):

1. Original SPT order: Job D → Job A → Job C → Job B
2. Simulate processing with breakdown:
- Job D: 0 → 40
- Job A: Starts at 40, breakdown at 91 (51 min completed), repair 31 min, resume 2 min → completes at 124
- Job C: 124 → 211
- Job B: 211 → 301

3. Total makespan: 301 minutes
4. Delay caused by breakdown: 31 minutes

Answer: 301 minutes

Key Strategy: Simulate the timeline, account for breakdown during active job processing.

Question 12

A machine needs to process 4 jobs. Processing times: - Job D: 87 minutes - Job E: 47 minutes - Job B: 80 minutes - Job A: 38 minutes The machine breaks down at 106 minutes and takes 25 minutes to repair. Jobs are scheduled using Shortest Processing Time (SPT) first rule. What is the total completion time (makespan) after handling the breakdown?
Step-by-step solution (Breakdown Recovery):

1. Original SPT order: Job A → Job E → Job B → Job D
2. Simulate processing with breakdown:
- Job A: 0 → 38
- Job E: 38 → 85
- Job B: Starts at 85, breakdown at 106 (21 min completed), repair 25 min, resume 59 min → completes at 190
- Job D: 190 → 277

3. Total makespan: 277 minutes
4. Delay caused by breakdown: 25 minutes

Answer: 277 minutes

Key Strategy: Simulate the timeline, account for breakdown during active job processing.

Question 13

A machine needs to process 4 jobs. Processing times: - Job D: 71 minutes - Job E: 79 minutes - Job A: 36 minutes - Job B: 51 minutes The machine breaks down at 68 minutes and takes 21 minutes to repair. Jobs are scheduled using Shortest Processing Time (SPT) first rule. What is the total completion time (makespan) after handling the breakdown?
Step-by-step solution (Breakdown Recovery):

1. Original SPT order: Job A → Job B → Job D → Job E
2. Simulate processing with breakdown:
- Job A: 0 → 36
- Job B: Starts at 36, breakdown at 68 (32 min completed), repair 21 min, resume 19 min → completes at 108
- Job D: 108 → 179
- Job E: 179 → 258

3. Total makespan: 258 minutes
4. Delay caused by breakdown: 21 minutes

Answer: 258 minutes

Key Strategy: Simulate the timeline, account for breakdown during active job processing.

Question 14

A machine needs to process 4 jobs. Processing times: - Job E: 37 minutes - Job A: 61 minutes - Job B: 85 minutes - Job C: 33 minutes The machine breaks down at 114 minutes and takes 23 minutes to repair. Jobs are scheduled using Shortest Processing Time (SPT) first rule. What is the total completion time (makespan) after handling the breakdown?
Step-by-step solution (Breakdown Recovery):

1. Original SPT order: Job C → Job E → Job A → Job B
2. Simulate processing with breakdown:
- Job C: 0 → 33
- Job E: 33 → 70
- Job A: Starts at 70, breakdown at 114 (44 min completed), repair 23 min, resume 17 min → completes at 154
- Job B: 154 → 239

3. Total makespan: 239 minutes
4. Delay caused by breakdown: 23 minutes

Answer: 239 minutes

Key Strategy: Simulate the timeline, account for breakdown during active job processing.

Question 15

A machine needs to process 4 jobs. Processing times: - Job E: 42 minutes - Job B: 53 minutes - Job C: 83 minutes - Job A: 37 minutes The machine breaks down at 66 minutes and takes 24 minutes to repair. Jobs are scheduled using Shortest Processing Time (SPT) first rule. What is the total completion time (makespan) after handling the breakdown?
Step-by-step solution (Breakdown Recovery):

1. Original SPT order: Job A → Job E → Job B → Job C
2. Simulate processing with breakdown:
- Job A: 0 → 37
- Job E: Starts at 37, breakdown at 66 (29 min completed), repair 24 min, resume 13 min → completes at 103
- Job B: 103 → 156
- Job C: 156 → 239

3. Total makespan: 239 minutes
4. Delay caused by breakdown: 24 minutes

Answer: 239 minutes

Key Strategy: Simulate the timeline, account for breakdown during active job processing.

Question 16

A machine needs to process 4 jobs. Processing times: - Job D: 87 minutes - Job E: 38 minutes - Job C: 83 minutes - Job A: 60 minutes The machine breaks down at 78 minutes and takes 44 minutes to repair. Jobs are scheduled using Shortest Processing Time (SPT) first rule. What is the total completion time (makespan) after handling the breakdown?
Step-by-step solution (Breakdown Recovery):

1. Original SPT order: Job E → Job A → Job C → Job D
2. Simulate processing with breakdown:
- Job E: 0 → 38
- Job A: Starts at 38, breakdown at 78 (40 min completed), repair 44 min, resume 20 min → completes at 142
- Job C: 142 → 225
- Job D: 225 → 312

3. Total makespan: 312 minutes
4. Delay caused by breakdown: 44 minutes

Answer: 312 minutes

Key Strategy: Simulate the timeline, account for breakdown during active job processing.

Question 17

A machine needs to process 4 jobs. Processing times: - Job D: 41 minutes - Job E: 74 minutes - Job A: 87 minutes - Job C: 42 minutes The machine breaks down at 97 minutes and takes 19 minutes to repair. Jobs are scheduled using Shortest Processing Time (SPT) first rule. What is the total completion time (makespan) after handling the breakdown?
Step-by-step solution (Breakdown Recovery):

1. Original SPT order: Job D → Job C → Job E → Job A
2. Simulate processing with breakdown:
- Job D: 0 → 41
- Job C: 41 → 83
- Job E: Starts at 83, breakdown at 97 (14 min completed), repair 19 min, resume 60 min → completes at 176
- Job A: 176 → 263

3. Total makespan: 263 minutes
4. Delay caused by breakdown: 19 minutes

Answer: 263 minutes

Key Strategy: Simulate the timeline, account for breakdown during active job processing.

Question 18

A machine needs to process 4 jobs. Processing times: - Job B: 57 minutes - Job E: 58 minutes - Job D: 56 minutes - Job C: 33 minutes The machine breaks down at 95 minutes and takes 27 minutes to repair. Jobs are scheduled using Shortest Processing Time (SPT) first rule. What is the total completion time (makespan) after handling the breakdown?
Step-by-step solution (Breakdown Recovery):

1. Original SPT order: Job C → Job D → Job B → Job E
2. Simulate processing with breakdown:
- Job C: 0 → 33
- Job D: 33 → 89
- Job B: Starts at 89, breakdown at 95 (6 min completed), repair 27 min, resume 51 min → completes at 173
- Job E: 173 → 231

3. Total makespan: 231 minutes
4. Delay caused by breakdown: 27 minutes

Answer: 231 minutes

Key Strategy: Simulate the timeline, account for breakdown during active job processing.

Question 19

A machine needs to process 4 jobs. Processing times: - Job E: 47 minutes - Job D: 54 minutes - Job B: 50 minutes - Job A: 84 minutes The machine breaks down at 92 minutes and takes 27 minutes to repair. Jobs are scheduled using Shortest Processing Time (SPT) first rule. What is the total completion time (makespan) after handling the breakdown?
Step-by-step solution (Breakdown Recovery):

1. Original SPT order: Job E → Job B → Job D → Job A
2. Simulate processing with breakdown:
- Job E: 0 → 47
- Job B: Starts at 47, breakdown at 92 (45 min completed), repair 27 min, resume 5 min → completes at 124
- Job D: 124 → 178
- Job A: 178 → 262

3. Total makespan: 262 minutes
4. Delay caused by breakdown: 27 minutes

Answer: 262 minutes

Key Strategy: Simulate the timeline, account for breakdown during active job processing.

Question 20

A machine needs to process 4 jobs. Processing times: - Job A: 36 minutes - Job D: 64 minutes - Job E: 60 minutes - Job C: 75 minutes The machine breaks down at 90 minutes and takes 34 minutes to repair. Jobs are scheduled using Shortest Processing Time (SPT) first rule. What is the total completion time (makespan) after handling the breakdown?
Step-by-step solution (Breakdown Recovery):

1. Original SPT order: Job A → Job E → Job D → Job C
2. Simulate processing with breakdown:
- Job A: 0 → 36
- Job E: Starts at 36, breakdown at 90 (54 min completed), repair 34 min, resume 6 min → completes at 130
- Job D: 130 → 194
- Job C: 194 → 269

3. Total makespan: 269 minutes
4. Delay caused by breakdown: 34 minutes

Answer: 269 minutes

Key Strategy: Simulate the timeline, account for breakdown during active job processing.
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