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Master Machine Breakdown Recovery - Beginner Level Problems Machine Breakdown Recovery BEGINNER

Excel in competitive exams with this skill builder ⚡ worksheet on Machine Breakdown Recovery. Worksheet 3 of 10 contains 20 beginner-level problems. Target your step-by-step problem solving skills while practicing machine breakdown recovery practice, machine breakdown recovery for competitive exams, and how to solve machine breakdown recovery.

📝 Worksheet 3 of 10 • 20 questions • ⏱️ Estimated time: 20 minutes • 🎯 Beginner level

What you'll learn in this worksheet:
Your progress through Machine Breakdown Recovery
Worksheet 3 of 10 (22% complete)

Question 1

A machine needs to process 4 jobs. Processing times: - Job B: 70 minutes - Job A: 48 minutes - Job C: 45 minutes - Job E: 55 minutes The machine breaks down at 83 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 A → Job E → Job B
2. Simulate processing with breakdown:
- Job C: 0 → 45
- Job A: Starts at 45, breakdown at 83 (38 min completed), repair 27 min, resume 10 min → completes at 120
- Job E: 120 → 175
- Job B: 175 → 245

3. Total makespan: 245 minutes
4. Delay caused by breakdown: 27 minutes

Answer: 245 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 C: 63 minutes - Job D: 43 minutes - Job B: 73 minutes - Job A: 85 minutes The machine breaks down at 68 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 B → Job A
2. Simulate processing with breakdown:
- Job D: 0 → 43
- Job C: Starts at 43, breakdown at 68 (25 min completed), repair 19 min, resume 38 min → completes at 125
- Job B: 125 → 198
- Job A: 198 → 283

3. Total makespan: 283 minutes
4. Delay caused by breakdown: 19 minutes

Answer: 283 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 A: 34 minutes - Job E: 67 minutes - Job D: 90 minutes - Job B: 63 minutes The machine breaks down at 76 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 B → Job E → Job D
2. Simulate processing with breakdown:
- Job A: 0 → 34
- Job B: Starts at 34, breakdown at 76 (42 min completed), repair 34 min, resume 21 min → completes at 131
- Job E: 131 → 198
- Job D: 198 → 288

3. Total makespan: 288 minutes
4. Delay caused by breakdown: 34 minutes

Answer: 288 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 C: 82 minutes - Job D: 85 minutes - Job E: 37 minutes - Job A: 38 minutes The machine breaks down at 89 minutes and takes 28 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 → 37
- Job A: 37 → 75
- Job C: Starts at 75, breakdown at 89 (14 min completed), repair 28 min, resume 68 min → completes at 185
- Job D: 185 → 270

3. Total makespan: 270 minutes
4. Delay caused by breakdown: 28 minutes

Answer: 270 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 E: 35 minutes - Job B: 61 minutes - Job D: 32 minutes The machine breaks down at 87 minutes and takes 42 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 B → Job A
2. Simulate processing with breakdown:
- Job D: 0 → 32
- Job E: 32 → 67
- Job B: Starts at 67, breakdown at 87 (20 min completed), repair 42 min, resume 41 min → completes at 170
- Job A: 170 → 232

3. Total makespan: 232 minutes
4. Delay caused by breakdown: 42 minutes

Answer: 232 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 C: 69 minutes - Job D: 68 minutes - Job B: 36 minutes - Job A: 90 minutes The machine breaks down at 61 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 B → Job D → Job C → Job A
2. Simulate processing with breakdown:
- Job B: 0 → 36
- Job D: Starts at 36, breakdown at 61 (25 min completed), repair 31 min, resume 43 min → completes at 135
- Job C: 135 → 204
- Job A: 204 → 294

3. Total makespan: 294 minutes
4. Delay caused by breakdown: 31 minutes

Answer: 294 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 A: 62 minutes - Job B: 64 minutes - Job D: 51 minutes - Job E: 83 minutes The machine breaks down at 69 minutes and takes 32 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 B → Job E
2. Simulate processing with breakdown:
- Job D: 0 → 51
- Job A: Starts at 51, breakdown at 69 (18 min completed), repair 32 min, resume 44 min → completes at 145
- Job B: 145 → 209
- Job E: 209 → 292

3. Total makespan: 292 minutes
4. Delay caused by breakdown: 32 minutes

Answer: 292 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 B: 56 minutes - Job D: 56 minutes - Job C: 64 minutes - Job E: 33 minutes The machine breaks down at 82 minutes and takes 45 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 C
2. Simulate processing with breakdown:
- Job E: 0 → 33
- Job B: Starts at 33, breakdown at 82 (49 min completed), repair 45 min, resume 7 min → completes at 134
- Job D: 134 → 190
- Job C: 190 → 254

3. Total makespan: 254 minutes
4. Delay caused by breakdown: 45 minutes

Answer: 254 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 B: 63 minutes - Job D: 42 minutes - Job A: 61 minutes - Job C: 82 minutes The machine breaks down at 110 minutes and takes 41 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 B → Job C
2. Simulate processing with breakdown:
- Job D: 0 → 42
- Job A: 42 → 103
- Job B: Starts at 103, breakdown at 110 (7 min completed), repair 41 min, resume 56 min → completes at 207
- Job C: 207 → 289

3. Total makespan: 289 minutes
4. Delay caused by breakdown: 41 minutes

Answer: 289 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 B: 31 minutes - Job D: 73 minutes - Job E: 31 minutes - Job A: 71 minutes The machine breaks down at 118 minutes and takes 26 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 A → Job D
2. Simulate processing with breakdown:
- Job B: 0 → 31
- Job E: 31 → 62
- Job A: Starts at 62, breakdown at 118 (56 min completed), repair 26 min, resume 15 min → completes at 159
- Job D: 159 → 232

3. Total makespan: 232 minutes
4. Delay caused by breakdown: 26 minutes

Answer: 232 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 B: 46 minutes - Job E: 68 minutes - Job C: 65 minutes - Job D: 44 minutes The machine breaks down at 76 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 D → Job B → Job C → Job E
2. Simulate processing with breakdown:
- Job D: 0 → 44
- Job B: Starts at 44, breakdown at 76 (32 min completed), repair 23 min, resume 14 min → completes at 113
- Job C: 113 → 178
- Job E: 178 → 246

3. Total makespan: 246 minutes
4. Delay caused by breakdown: 23 minutes

Answer: 246 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 C: 83 minutes - Job E: 61 minutes - Job B: 87 minutes - Job D: 49 minutes The machine breaks down at 109 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 D → Job E → Job C → Job B
2. Simulate processing with breakdown:
- Job D: 0 → 49
- Job E: Starts at 49, breakdown at 109 (60 min completed), repair 21 min, resume 1 min → completes at 131
- Job C: 131 → 214
- Job B: 214 → 301

3. Total makespan: 301 minutes
4. Delay caused by breakdown: 21 minutes

Answer: 301 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 C: 70 minutes - Job E: 36 minutes - Job B: 63 minutes - Job A: 45 minutes The machine breaks down at 60 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 E → Job A → Job B → Job C
2. Simulate processing with breakdown:
- Job E: 0 → 36
- Job A: Starts at 36, breakdown at 60 (24 min completed), repair 31 min, resume 21 min → completes at 112
- Job B: 112 → 175
- Job C: 175 → 245

3. Total makespan: 245 minutes
4. Delay caused by breakdown: 31 minutes

Answer: 245 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 D: 53 minutes - Job E: 58 minutes - Job A: 71 minutes - Job C: 90 minutes The machine breaks down at 92 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 D → Job E → Job A → Job C
2. Simulate processing with breakdown:
- Job D: 0 → 53
- Job E: Starts at 53, breakdown at 92 (39 min completed), repair 18 min, resume 19 min → completes at 129
- Job A: 129 → 200
- Job C: 200 → 290

3. Total makespan: 290 minutes
4. Delay caused by breakdown: 18 minutes

Answer: 290 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: 54 minutes - Job A: 76 minutes - Job B: 78 minutes - Job D: 45 minutes The machine breaks down at 67 minutes and takes 45 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 A → Job B
2. Simulate processing with breakdown:
- Job D: 0 → 45
- Job E: Starts at 45, breakdown at 67 (22 min completed), repair 45 min, resume 32 min → completes at 144
- Job A: 144 → 220
- Job B: 220 → 298

3. Total makespan: 298 minutes
4. Delay caused by breakdown: 45 minutes

Answer: 298 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 A: 71 minutes - Job E: 60 minutes - Job C: 34 minutes - Job B: 43 minutes The machine breaks down at 98 minutes and takes 22 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 B → Job E → Job A
2. Simulate processing with breakdown:
- Job C: 0 → 34
- Job B: 34 → 77
- Job E: Starts at 77, breakdown at 98 (21 min completed), repair 22 min, resume 39 min → completes at 159
- Job A: 159 → 230

3. Total makespan: 230 minutes
4. Delay caused by breakdown: 22 minutes

Answer: 230 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 E: 74 minutes - Job C: 74 minutes - Job D: 72 minutes - Job B: 85 minutes The machine breaks down at 62 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: Starts at 0, breakdown at 62 (62 min completed), repair 33 min, resume 10 min → completes at 105
- Job E: 105 → 179
- Job C: 179 → 253
- Job B: 253 → 338

3. Total makespan: 338 minutes
4. Delay caused by breakdown: 33 minutes

Answer: 338 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 E: 73 minutes - Job B: 48 minutes - Job A: 76 minutes - Job D: 86 minutes The machine breaks down at 88 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 B → Job E → Job A → Job D
2. Simulate processing with breakdown:
- Job B: 0 → 48
- Job E: Starts at 48, breakdown at 88 (40 min completed), repair 34 min, resume 33 min → completes at 155
- Job A: 155 → 231
- Job D: 231 → 317

3. Total makespan: 317 minutes
4. Delay caused by breakdown: 34 minutes

Answer: 317 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 A: 84 minutes - Job E: 75 minutes - Job B: 42 minutes - Job C: 52 minutes The machine breaks down at 87 minutes and takes 15 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 E → Job A
2. Simulate processing with breakdown:
- Job B: 0 → 42
- Job C: Starts at 42, breakdown at 87 (45 min completed), repair 15 min, resume 7 min → completes at 109
- Job E: 109 → 184
- Job A: 184 → 268

3. Total makespan: 268 minutes
4. Delay caused by breakdown: 15 minutes

Answer: 268 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 C: 69 minutes - Job D: 62 minutes - Job A: 76 minutes - Job E: 88 minutes The machine breaks down at 70 minutes and takes 40 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 A → Job E
2. Simulate processing with breakdown:
- Job D: 0 → 62
- Job C: Starts at 62, breakdown at 70 (8 min completed), repair 40 min, resume 61 min → completes at 171
- Job A: 171 → 247
- Job E: 247 → 335

3. Total makespan: 335 minutes
4. Delay caused by breakdown: 40 minutes

Answer: 335 minutes

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