SMED or Single Minute Exchange of Die is the process of minimizing changeover or setup time. It entails identifying and eliminating any unneeded aspects of the transition process. When a piece of industrial equipment needs to be replaced, the downtime can be costly and unexpected. SMED is essential to lean manufacturing since it may eliminate waste, increase productivity, and cut costs.
However, there is much more to what this strategy is, what it delivers, and how it offers than a simple full-form meaning when it comes to adopting it. Let’s go ahead and go over everything in detail.
The Basics of Single-Minute Exchange of Die:
The SMED system is a lean manufacturing principle that accomplishes more with less while providing maximum value to the customer. Its goal is to shorten the time required to complete changeovers in equipment machines. This incentivizes plant personnel to complete as many processes as possible before the switch, have teams working in parallel, and have a standardized and optimized working procedure.
The goal is to shorten any changeover time from hours to less than ten minutes, thus the Single Minute Exchange of Dies. Dies are specialized manufacturing tools that must be re-setup when production models change, resulting in downtime. Shigeo Shigo, a Japanese industrial engineer, is credited with inventing the SMED system. Using this strategy, he reduced changeover times in the businesses he dealt with by 94%. It is only sometimes possible to reduce the machinery replacement time to less than 10 minutes, but in most cases, this is achievable.
Why is SMED Important?
Lean manufacturing seeks to minimize waste and increase efficiency wherever possible within a given system.
According to the Lean methodology, waste is one of the three key areas that must be addressed: the loss of Muda, Muray Muri. Single Minute Exchange of Dies is responsible for these three sorts of waste. However, the elimination of mura is the primary issue (unevenness).
When meeting client expectations, every smaller batch must be able to be processed to establish a smooth and predictable process flow. The ongoing need to update equipment is the major impediment to manufacturing lower volumes. These changes are time-consuming and costly and must be recouped in a more practical approach to be profitable.
Since the changeover period for some pieces of machinery can last several hours or even days, it is necessary to maximize the production of specific machines in terms of their busy, productive time. Because the batch size is maximized, this results in the most efficient use of the available resources. Only when there is a need to change the process do inefficiencies become apparent.
Reduced setup times for each changeover are essential if smaller batches are to be produced in an economically viable way. As a result, the internal setup must be minimized as much as feasible so that the changeover time has as minimal an impact on the manufacturing process as possible.
In SMED or Single Minute Exchange of Dies, changeovers are built through a series of processes known as elements. Components are classified into two types:
- Internal Components
These elements must be applied or updated after the device has been turned off. Examples include:
- Removing outdated tools.
- Replacing them.
- Adjusting the material feed.
- Changing the program parameters.
Consider this to be a Formula One pit stop. The automobile enters the pit lane, stops, and the crew members change the tires.
- External Factors
When the gadget is in use, external items can be applied or added. Purchase of new material feeds, acquisition of new tools, return of old tools or storage of old tools, documentation of suitable processes, or licensing request are a few examples. While the car is still on the circuit, the team is already preparing the tires, preparing tools, and positioning technicians. As a result, the crew can finish the operation in its entirety in a matter of seconds once the automobile comes to a stop.
The SMED or Single Minute Exchange of Dies procedure consists of several steps. You can implement this LEAN approach by:
1. Keep internal and external setup processes separate.
Elements involved in the changeover process that can be managed with little or no change while the production equipment is running are identified during this step and then carried out before or after the switch. It is common for this procedure to result in a 50% reduction in changeover times.
The team must ask if each element and sub-process can be performed while the equipment is in operation. If the answer is true, the element is external.
2. Standardize external configuration processes
All external phases can be identified and standardized using movies or flowcharts during this phase. It means that you can complete such tasks while the procedure is running. If this is not done carefully, there may be times when the tools must be gathered when the machines are not running. This extends the switching time beyond what is necessary.
3. Change internal setup processes to external setup processes
During this step, the changeover process is extensively examined to make as many internal elements as feasible external. During this step, the team must consider whether there is a way to turn internal elements into external ones, what that approach would be, and how to do so.
The result is a list of items that you can take further. This priority list is similar to a cost-benefit analysis in several aspects.
4. Improve internal communication processes
‘Only the final turn of the bolt locks the part in its place,’ Shigeo Shingo once said. What remains after this is just movement, and that can be discarded.
The concept is that the bolt, for example, can be replaced by shorter, spring-loaded clamps that hold the part in place. The time previously spent twisting the bolt is now saved. Various machines or tools are modified to provide standard sizes. Moreover, you can also reduce mounting points to reduce the number of steps required to complete the work.
5. Enhance external setup procedures
The remaining external elements are assessed during this step. The idea is to streamline and simplify these processes to save time.
As with the previous steps, the team evaluates how to execute this part in less time. How can we make this simpler? A cost-benefit analysis is also beneficial for assessing if it is efficient enough.
6. Repeat SMED several times.
You can achieve regular time savings by meticulously analyzing the entire process over and over. For example, new technologies or other important insights offer chances to optimize the process via video analysis.
The following benefits will be realized when the Single Minute Exchange of Dies approach is used correctly. Among all the benefits, Single Minute Exchange of Dies or SMED most notably offers enhanced productivity. Now let’s dive into some additional benefits:
- Increased Productivity: When the amount of time necessary for changeovers is reduced, the number of goods produced in an agreed period increases, as does the amount of time spent working. Non-value-added “Muda” is eliminated.
- A Flexible Manufacturing Process is Conceivable: because it is possible to produce only a modest quantity of goods and because switching between different types of goods is straightforward.
- Improved Customer Satisfaction: It leads to increased customer satisfaction because their needs are met on time.
- Product Quality Improvement: This helps to reduce the number of defective goods generated when the machines are being set up.
- Lowering the Cost of Inventory Maintenance: Lean production, which allows for less output and eliminates the need for product storage, reduces the expenses associated with inventory management.
- Lowering the Cost of Maintenance: Because fewer manual operations, adjustments, and stacking are necessary, the risks of dies dropping, striking, or being physically damaged are reduced.
- A Reduction in Workplace Accidents: The number of occupational accidents throughout this process has decreased due to the easier and shorter preparation process.
The purpose of digital lean manufacturing is to eliminate waste. Manufacturers are taking initiatives to improve material workflows following change-out to achieve even faster start-up times by utilizing SMED or Single Minute Exchange of Dies. A smart, connected manufacturing line gives firms even more information about the operation and efficiency of their items.