Keep Production Lines Efficient
It's a build-to-order manufacturing environment and that means frequent changeovers in your production line. And each time you make changes to produce a new item, you suffer significant downtime.
But there may be ways to shave time off those non-productive periods. These four suggestions have proven to buy manufacturers time:
Lean Material Stocking
Instead of trying to trim retooling time, try eliminating it with a lean material stocking system.
An established principle of time management is to handle each piece of paper just once. It's rare to achieve that efficiency, but aiming for it makes you think about unnecessary steps. Applying that principle to parts and maintenance, compare these two scenarios of the typical route from delivery to production:
Before the lean method:
Parts are stocked until needed for production.
Parts are assembled into kits and sent to production.
The parts are ready for production when needed.
After the lean method:
Parts are sorted and sent to carts holding bins labeled for each part number.
When production is ready, the cart is moved to the job.
What the lean material stock system does:
Eliminates the labor-intensive steps of storing, locating and retrieving materials and assembling kits.
Provides visual inventory control, because by looking at a bin, you can see if a part is in short supply.
Offers just-in-time capabilities. Almost as soon as materials are received, they are ready to be used in production.
1. Measure setup time. It should be a key metric in batch-driven processes. If you're not establishing goals and monitoring setup time, it can get away from you.
2. Mimic NASCAR. One company occasionally stops production to hold a contest, putting together "pit crews" to see who can set up a machine the fastest. The winning team's time becomes the new goal. Winners get bragging rights.
3. Think Japanese. Manufacturers in Japan are known for their efficiency and ability to make quick changes. One of the techniques they use is Kaizen. Assemble a team that cuts across disciplines and spend three to five days tackling a process improvement problem. For example, one company had a team reconfigure work and storage areas. It reduced setup time from 6 hours to 40 minutes.
Several factors contribute to Kaizen success:
- Holding the event elevates the problem to priority level.
- Include people on the team who have no production experience, along with those who do. This improves the problem-solving process.
- Follow the Kaizen event outline.
- Set the expectation that the team will make a major achievement in a very short time.
4. Consider another Japanese method. Japanese industrial engineer Shigeo Shingo developed the "Single Minute Exchange of Dies" process for Toyota as an essential component of just-in-time manufacturing. He maintained that most approaches to reducing setup time limit their success by focusing on improving employee skills rather than on making changes in the process that lower the skills needed. Shingo describes how to implement SMED in his book, A Revolution in Manufacturing:
- Analyze the production system thoroughly and the role setup plays in that system.
- Study the internal setup, or those processes that can be carried out only when the machine is idle, for example, changing dies.
- Study external setup, or those processes that can be carried out while the machine is running, such as transporting dies or checking availability of materials.
- Determine how internal setup can be converted to external setup, thus streamlining the entire process.
The best changeover is no changeover. Look at ways products can be redesigned to share more of the same parts. Moreover, if you're running small batches of similar products, you might be able to avoid changeover by taking some processes offline.