The path towards continuous improvement in your lean journey is not always as clear as you’d like it to be. Many of the processes and methodologies behind Lean take time before your organization has success with them. It’s a learning process well worth the investment, but can be frustrating at times. Same goes for the Lean process known as Single Minute Exchange of Die (SMED). The increased efficiency and reduction of costly inventory that results from SMED, only comes when your organization has fully committed and dedicated the time to fully understand the process.
Background of Single Minute Exchange of Die or SMED
The SMED process was developed by Dr. Shigeo Shingo in Japan during the sixties and early seventies at Toyota. Dr. Shingo was given the challenge of increasing production capacity without purchasing new equipment. His research at first was mostly spent observing machines in action and trying to understand how to make them run faster. However, this was not giving him the information he was looking for.
To his surprise, his aha moment came when he observed a machine sitting idle. While spending all the time focused on the machine in action, he failed to realize the lack of emphasis on the machine’s cycle time. When a production order was complete the machine would lay idle while workers slowly gathered the materials for the next order. Dr. Shingo then realized that in order to achieve full production capacity, you have to reduce setup and changeover time.
His new focus led him to realize that changing production equipment from the last good piece to the first good piece, should take less than 10 minutes. Which is where the term “Single Minute Exchange of Dies” (SMED) came from.
What Can SMED Do For You?
Most people refer to SMED today as “quick changeover” or “setup reduction.” Even though it was originally developed to improve die-press and machine-tool setups, the concept applies to all changeovers in all types of product setups.
In the book Quick Changeover Simplified, authors Fletcher Birmingham and Jim Jelinek offer six reasons why a quick changeover process like SMED will help benefit your company. They are as follows:
- Simplify your manufacturing process. A quick setup and changeover program simplifies processes and makes manufacturing jobs easier and more fulfilling for employees. This leads to happier employees, which leads to a lower turn-over rate.
- Improve the quality of products. When you define, simplify, and control your manufacturing processes, the end result will be a better, higher quality product.
- Increase throughput. A quick setup program allows an increase in throughput, helping to improve deliveries. Improved deliveries help customers sell more products, thus increasing their need to order more products from you to keep up with demand.
- Permit smaller lots. The old rule of thumb was to produce goods in large lots because long setup times make it costly to change the process frequently. However producing large lots for this reason has several disadvantages, including:
~Inventory waste: storing what doesn’t sell costs money and ties up company resources without adding value.
~Quality loss: storing unsold inventory increases the chance that it will have to be scrapped or reworked.
~Delay waste: customers must wait for the company to produce entire lots, rather than the quantity they need.
~Non-standardized setups: Infrequent setups often aren’t standardized; thus they are difficult and risky.
- Make your company more competitive. A quick setup and changeover program reduces the time , cost, and resources associated with switching from one manufacturing job to the next. Any savings you have can then be passed along to your customer to make you that much more competitive.
- Save jobs. Not implementing a quick setup program makes your company noncompetitive because it needs to absorb the cost of lost potential savings that could have benefited your company and customers.
These benefits of SMED are just the start of the continued improvement you will see to your facility in the long and short term. Stay tuned for more on SMED, including tips on how to implement SMED into your Lean facility.