Brief Guide: Single-Minute Exchange of Dies (SMED)

In today’s manufacturing world, downtime is the enemy of productivity and competitiveness. One of the best ways to beat downtime is Single-Minute Exchange of Dies (SMED), a lean manufacturing technique that reduces setup and changeover times to optimize the changeover process. This guide will cover the concept, benefits and implementation of SMED so you can get your processes streamlined and efficient.

What is Single-Minute Exchange of Dies (SMED)?

SMED or Single-Minute Exchange of Dies is a methodology that reduces the changeover time to switch from one process to another. The goal is to change over in less than 10 minutes hence the name ‘single-minute’ or ‘minute exchange of die’.

Shigeo Shingo, a Japanese industrial engineer and one of the founders of lean manufacturing developed the concept. Originally applied to die changes in manufacturing presses, SMED has since been applied to automotive, electronics and food industries.

Key Principles of SMED

SMED is based on a few simple principles to make changeovers faster:

• Internal and External Activities: Recognizing internal and external elements is crucial. Internal are tasks that can only be done when the machine is stopped, external are tasks that can be done while the machine is running. Move as many tasks as possible to external activities and downtime will be much reduced. Additionally, convert internal elements into external elements to further streamline the process. This can be achieved by evaluating internal elements that can be transformed, prioritizing them based on potential benefits, and conducting a cost/benefit analysis to ensure the changes are viable and efficient.
• Automate or Mechanize Where Possible: Introduce automation or mechanized solutions to further reduce the manual effort required for setup changes.
• Make Everything Setup: Simplify and optimize internal and external activities. Standardize tools, layout the workstation, reduce movement.

Benefits of SMED

SMED brings many benefits to your manufacturing operation:

• Less Downtime: Less changeover time means machines are idle for less time, higher OEE and less equipment downtime.
• More Flexibility: Faster changeovers means you can run smaller production batches and reduce inventory, to meet customer demand better.
• More Productivity: Operators can focus on production not setup, more throughput.
• Cost Savings: Less changeover time means lower labor costs and less waste, overall cost efficiency.
• Enhanced Quality: Standardized and streamlined setups minimize the risk of errors and defects.

Steps to Implement SMED

SMED is a process divided into 4 steps:

1. Observe the Current Process: Start by documenting the current changeover process. Record all activities, timing and challenges. This is the baseline for waste.
2. Split Internal and External Activities: Categorize each activity as internal or external changeover elements. Identifying and categorizing these elements is crucial to optimize the process. Look for tasks that can be externalised and separate external elements to reduce downtime. Shifting internal elements to external elements can significantly reduce time and costs.
3. Simplify Internal Activities: Simplify and optimise internal tasks. Use quick change tools, reduce fasteners and design fixtures for easy setup.
4. Standardize and Train: Write down the new process and train staff. Review and refine regularly.

SMED in Action

1. Automotive Manufacturing
Car manufacturers use SMED to reduce changeover time between different models on a production line. Standardized tools and modular components mean what used to take hours can now take minutes.

2. Food Manufacturing
In food production, SMED enables rapid transition from one product line to another by pre-organising internal and external components, for example when switching from one snack flavour to another. In this way, waste and downtime are minimised and consumer demand for variety is met.

3. Electronics Manufacturing:
Electronics manufacturers use SMED to switch between different circuit board designs. By pre-organizing tools and materials and identifying internal and external components that can be prepared while the machine is running they can adapt to changes in production schedules more quickly.

Challenges

While SMED offers many benefits, implementing it can be tough. Common hurdles:

• Resistance to Change: Employees do not want to change their changeover methods. Communication and training are key to getting them to agree.
• Initial Outlay: The cost of new tools, fixtures or equipment modifications can seem high. But the payback is usually worth it.
• Complex Processes: Highly complex setups require more analysis and creative thinking to get each internal element right.

Advanced SMED Strategies

Once you have the basic SMED principles in place, advanced strategies can take it to the next level. These include:

• Technology: Automation and digital tools like sensors and software can monitor setup times and identify internal and external weaknesses. Predictive analytics can help predict delays and schedule accordingly.
• Modular Design: Design equipment and components to be modular so that replacements and setups are faster and external components are always ready. This is especially useful in industries with many product variations.
• Kaizen Events: Run focused improvement workshops or Kaizen events to help teams identify and implement SMED improvements especially in internal setup. Collaboration during these events gets employees on board.
• Cross-Trained Employees: Train employees across multiple roles so that setups can be done efficiently even in case of absenteeism or high demand.

Future of SMED

As industries change the principles of SMED still apply to optimise the manufacturing process. With Industry 4.0 SMED can be integrated with smart manufacturing technologies to make it even more efficient. For example IoT devices can provide real time data on machine performance so you can make quicker and more informed decisions during changeovers.

And with the focus on sustainability SMED plays a part in reducing waste. By allowing smaller batch sizes and minimising equipment changeover downtime SMED is leaner and more green manufacturing.

Summary

Single-Minute Exchange of Dies (SMED) is a powerful way to reduce changeover times and increase manufacturing efficiency through the SMED process. By following the principles and implementing the steps systemically you can reduce downtime, increase flexibility and save big. Whether you’re in automotive, electronics or any other industry SMED is a proven path to leaner more agile operations.

With continuous improvement and adapting to new technologies SMED is at the heart of lean manufacturing and helps businesses to meet the demands of a competitive and changing world.