Model Answer
0 min readIntroduction
In operations management, optimizing production processes is crucial for efficiency and cost-effectiveness. A key aspect of this optimization involves identifying and managing bottlenecks – the workstations that limit the overall throughput of the system. Understanding the impact of changes in processing times at different workstations on overall production and Work-In-Process (WIP) is fundamental to effective production planning and control. This answer will analyze the given production process, calculate the number of units produced, and assess the effect of a processing time reduction at workstation S3 on WIP levels.
(i) Units Produced in an 8-Hour Day
The production process has four workstations: S1, S2, S3, and S4. The processing times for each workstation are as follows:
| Workstation | Processing Time (minutes/unit) |
|---|---|
| S1 | 10 |
| S2 | 15 |
| S3 | 20 |
| S4 | 12 |
The bottleneck workstation is S2, as it has the longest processing time (15 minutes/unit). We are given that 2 units of S2 are available. This means S2 can process a maximum of 2 units simultaneously. An 8-hour day is equivalent to 480 minutes.
The maximum number of units S2 can process in a day is calculated as follows:
- Units processed by S2 per hour: 60 minutes / 15 minutes/unit = 4 units/hour
- Since 2 units can be processed simultaneously, the effective processing rate is 2 units every 7.5 minutes (15/2).
- Total units processed by S2 in 480 minutes: 480 minutes / 7.5 minutes/2 units = 64 units
Therefore, 64 units are produced in an 8-hour day. The throughput of the entire system is limited by the bottleneck workstation, S2.
(ii) Reduction in Work-In-Process (WIP) if S3 Processing Time is Reduced
If the processing time in S3 is reduced to 8 minutes, the bottleneck will shift to S2, as S2 still has the longest processing time (15 minutes). Reducing the processing time at a non-bottleneck workstation (like S3 initially was) does not necessarily reduce the overall Work-In-Process (WIP). This is because the system's throughput is still constrained by the bottleneck (S2).
Why? WIP is directly related to the cycle time and throughput of the system. The cycle time is determined by the bottleneck workstation. Reducing the processing time at S3 only allows units to move through S3 faster, but they will still accumulate at S2, waiting to be processed. The overall flow rate remains the same, dictated by S2.
To reduce WIP, the processing time at the bottleneck workstation (S2) needs to be reduced. If S2’s processing time were reduced, the cycle time would decrease, leading to a lower WIP level throughout the system. However, with S2 remaining the bottleneck, reducing S3’s processing time will primarily increase utilization at S3 and potentially reduce idle time, but it won’t significantly impact the overall WIP.
In fact, reducing S3’s processing time might even slightly increase WIP at S3 itself, as units will spend less time there and accumulate faster before moving to the bottleneck S2.
Conclusion
In conclusion, the production process is limited by the bottleneck workstation, S2, resulting in a throughput of 64 units per 8-hour day. Reducing the processing time at a non-bottleneck workstation like S3 does not inherently reduce the overall Work-In-Process (WIP) because the system’s throughput remains constrained by the bottleneck. Focusing on improving the bottleneck workstation is crucial for increasing throughput and reducing WIP levels. Effective operations management requires a thorough understanding of bottleneck analysis and its implications for production planning and control.
Answer Length
This is a comprehensive model answer for learning purposes and may exceed the word limit. In the exam, always adhere to the prescribed word count.