Introduction:
In this blog post, I want to share an interesting story from my experience working with an automotive parts supplier. This particular incident highlighted the importance of implementing lean manufacturing practices and how it can strengthen quality systems in the workplace.
Background:
The manufacturer was struggling with multiple customer complaints, despite having sufficient resources and efforts in place to prevent such issues. The problem revolved around a mounting bracket that was missing a hole, causing alarms in the customer’s equipment. The manufacturer had already shipped the same defective parts on three separate occasions, leading to severe consequences.
The Desperate Measure:
To prevent further issues, the manufacturer implemented a vision system and two layers of inspection. Additionally, they introduced a jig just before loading the parts onto trucks for shipping. This jig involved a simple stab pin check, ensuring that every part had the required hole before being loaded into the finished goods container.
The Curious Case:
Two weeks after this check was established, a part without the required hole was discovered. Reviewing the scrap logs revealed that there was a single part scrapped the previous day. The operator responsible for the process confirmed that she had placed the part in the scrap bin next to her station, following the correct procedure. However, upon checking the bin, it was inexplicably empty. How did that part end up in the customer’s finished goods bin?
The Investigation:
Determined to find answers, the team decided that the team leader would have a word with the janitor, who routinely checked waste and scrap bins across the plant after everyone had left for the day. The team leader inquired if the janitor had found anything in the scrap bin next to the manufacturing process.
The Janitor’s Revelation:
With a surprised expression, the janitor replied, “Yes, I find one part every few weeks.” Puzzled, the team leader asked what he did with the parts. The janitor explained, “I always wondered why someone would drop a part here. We don’t want to lose a part that we can still sell, so I place it in the bin next to it.”
Conclusion:
This incident with the missing hole in the mounting bracket taught the manufacturer valuable lessons about lean manufacturing principles. By implementing effective scrap management practices and ensuring a single-piece flow, they were able to prevent further mistakes and strengthen their quality systems.
Key Lean Manufacturing Ideas:
- Scrap Management:
This incident served as a reminder of the importance of effective scrap management. Scrap pieces should be placed in assigned areas away from good products. Practices such as labeling scrap parts with markers, attaching scrap tags, or spray painting them can make the scrap management system more efficient and prevent confusion.
2. Single Piece Flow:
To enhance efficiency and prevent mix-ups, there should be no provision to hand-load a part directly into the finished goods bin. Implementing chutes to guide parts into the appropriate locations and ejectors to shoot the parts into the finished goods bin are good practices that promote a single-piece flow. Additionally, the proximity of the scrap bin to the finished goods bin should be carefully considered in the process layout.
I would love to hear about your experiences with lean tools and practices that you’ve used to enhance quality systems in your workplace. Please share your insights in the comments below!