Single minute exchange of die (SMED)

Single-Minute Exchange of Die (SMED)

Successful manufacturing businesses thrive on efficiency and adding value to raw materials with minimal wasted resources. However, one type of waste, wasted time or idle time, in the form of lengthy equipment changeovers hinder efficiency, cost and eventually profitability. This downtime translates to lost production time, lost revenue for the business and overall efficiency reduction. What tool could we use to reduce this waste and turn this previously lost time into profit?

Here’s where the Single-Minute Exchange of Die (SMED) methodology steps in. Think of SMED as a practical approach specifically designed to streamline the process of changing tools or machine setups on your equipment to change production quickly to a different product, process or variant. It’s all about minimizing downtime (that frustrating period when your machines are idle and not producing) and maximizing your production potential and capacity.

“SMED (Single Minute Exchange of Die) is a systematic approach within lean manufacturing aimed at dramatically reducing the time it takes to switch between production runs on equipment.”

Understanding the SMED Concept: Beyond One Minute

The name “Single-Minute Exchange of Die” might make you think of super-fast changeovers. Sounds great, but the real goal of SMED is to achieve changeover times in under 10 minutes as a general rule of thumb. (Single digit)

But SMED is not just about speed! SMED is a way to cut out unnecessary steps when switching between jobs on your machines. SMED focuses on the essential activities needed for a smooth and efficient changeover, leading to a more streamlined production process overall.

SMED, or Single-Minute Exchange of Die itself, is a Lean manufacturing tool. It aims to complete as many steps as possible while the equipment is running (or processing) to save time and quickly change over to processing the next product. Usually production or machine changeovers are made up of a series of tasks and steps that can be classified in two different types of elements.

External Elements: By external elements, we mean activities that can be completed while the equipment is running. For example, in a machining setting, SMED might involve collecting the new cutting tools beforehand and setting them up on a separate tool holder station or preparing a mold or die ready for installation on the production line
Internal Elements: By internal elements, we mean activities that must be completed while the equipment is stopped for safety or practical reasons. For example, in machining, this might involve taking out the old tool from the machine and preparing the new one for accurate cutting or having to change the stamp die on a press to a different design

The Power of Efficiency: The Tangible Benefits of SMED

SMED offers a multitude of advantages to your manufacturing operation. Here are some key benefits to consider:

Boosted Production Efficiency: Implementing faster changeovers means enhanced production efficiency. Imagine a factory that makes bikes. Usually, it takes them a long time to switch between making red bikes and blue bikes. This time between switching colors is called production changeover downtime.
By getting faster at switching colors (faster changeover process), the factory can spend less time not making bikes and more time making them. This means they can produce more bikes overall without needing to stay open longer and increase sales revenue. It’s like having more production within the existing operational timeframe.
Reduced Costs: Changeovers can be like those little gaps in time that seem insignificant, but they can really add up. SMED helps identify and eliminate the unnecessary parts of those changeovers, making your production line run smoother and faster. Just like a streamlined routine saves you time in the morning, SMED helps save time in production, which means more products are made and more money is earned.
Enhanced Agility and Flexibility: With SMED, manufacturers can adapt and make what’s in demand right now instead of being stuck making a big batch of something nobody wants anymore, thus providing your manufacturing plant with flexibility to quickly adapt to changes in customer’s demands. Think of it like having a toolbox with many tools. Normally, switching between products requires a big changeover, like grabbing a whole new toolbox. With SMED, it’s like having some tools readily available (external setup) and some specific ones you can swap quickly (internal setup). This availability helps manufacturers make smaller batches of different products without any delay.
Optimized Inventory Levels: SMED helps manufacturers produce smaller batches of goods with more frequent production runs. With less space needed for stock, manufacturers can save their resources and working capital which can be invested in other areas to achieve better returns on capital.

The SMED Stages

SMED is a structured approach. It requires a systematic analysis of your changeover process. By following these key stages, you can identify areas for improvement and achieve dramatic reductions in changeover time:

Separation of Internal and External Setup: The first step of SMED involves identifying tasks and steps done during a changeover. Some tasks can be done while the machine is still running (external setup), like preparing tools or materials. Others require a complete machine stoppage (internal setup), like actually changing the tool itself. Think of changing a light bulb: you can unscrew the old one and clean the socket while the light is on (external setup), but screwing in the new bulb requires turning it off (internal setup).
Converting Internal Setup to External Setup: The next step of SMED is to see if any tasks that require stopping the machine (internal setup) can be done while it’s still running (converted to external setup). This might involve using special tools, making it easier to reach parts inside the machine, or using quick-release mechanisms. The goal is to minimize the downtime needed for changeovers. Imagine changing a tire: ideally, you’d loosen the lug nuts before jacking up the car (external setup) to save time spent waiting.
Optimizing Internal and External Setup: Optimizing internal and external setup is all about streamlining the changeover process to happen as quickly as possible. Manufacturers need to involve a team in analyzing and improving the changeover process. By using a designated set of tools for each specific changeover, manufacturers can save precious time.
Optimization organizes tools, components, consumables and materials in a way that minimizes unnecessary movement and delays. This process isn’t perfect at first. Regularly analyze each step of the changeover process, identify bottlenecks or areas that take too long, and then brainstorm solutions to refine your strategy for even faster changeovers. Think of this process as achieving a formula one pit stop efficiency level.
Continuous Improvement: SMED is like a training program for your pit crew (factory workers) to do equipment changeovers (like switching from one product to another) in record time. Your factory needs to keep using and improving its SMED skills. Perform regular check-ins to see how the changeovers are going, if there are any problems, and brainstorm ways to do things even faster. You need to track how long changeovers take. This is called “Setup Reduction Time” (SRT). By looking at this data, you can see exactly where things are slowing down and focus on improving those specific areas. Basically, SMED gives you the tools, but continuous practice and data analysis help you become a truly efficient factory churning out products at lightning speed.

SMED in Action: Real-World Example

Imagine a busy toy factory producing dolls one minute and zooming trucks the next. Frequent production line changes can be a bottleneck, leading to delays and missed deadlines. SMED ensures smooth transitions and keeps your deliveries running like clockwork.

SMED: A Streamlined Approach to Production Changeovers

SMED is all about the single-minute exchange of the die. It minimizes the time to switch between producing different items. Ideally, SMED strives for changeovers to occur in less than 10 minutes.

Here’s how it helps the toy factory:

Organized Toolkits: SMED promotes having separate toolkits dedicated to each specific toy and making sure that workers have everything they need.
Internal vs. External Tasks: SMED cleverly separates internal and external tasks. This distinction allows for efficient use of production time while preparing for the switch.
Ready Parts: SMED also promotes organization and ensures all necessary components are readily available before a production line changeover. This eliminates delays and keeps the transition smooth.

Benefits of SMED Implementation in this example:

By adopting SMED principles, the toy factory can reap several benefits, like:

Reduced downtime in changing over the type of toy produced,
Improved Response time (flexibility) and
Reduced Errors.

In essence, SMED acts as a valuable tool for toy factories, enabling them to operate smoothly and efficiently while producing a wide variety of toys for children.

SMED FAQ

Here are answers to some frequently asked questions about SMED:

What does SMED stand for?

SMED stands for Single Minute Exchange of Die. However, it’s important to understand that the “single minute” refers to the ideal outcome, aiming for changeover times in the single digits (less than 10 minutes).

What is the SMED technique?

SMED is a technique used in lean manufacturing to significantly reduce the amount of time it takes to change equipment from producing one product to another. It focuses on identifying and streamlining the changeover process, separating essential steps from those that can be done beforehand (external activities) or even eliminated.

Who is the father of SMED?

Shigeo Shingo, a Japanese industrial engineer, is widely credited as the father of SMED. He developed the concept while working at Toyota in the 1950s.

What is SMED in lean manufacturing?

SMED is a core principle of lean manufacturing. It aligns with the lean philosophy of eliminating waste and maximizing efficiency. By reducing changeover times, SMED helps manufacturers: Increase production output Improve responsiveness to customer demand Reduce labor costs Minimize material waste Enhance overall production flexibility

Conclusion

In today’s fast-paced manufacturing world, efficiency is king. SMED offers faster changeovers, reduced downtimes, cost savings, less working capital for businesses,the flexibility and adaptability for changing market trends. By implementing SMED, manufacturers gain a significant competitive edge and stay ahead of the pack.

Single minute exchange of die (SMED)