Everything to Know About Single-Minute Exchange of Die (SMED)

Suppose your plant runs a high-volume production line that needs to be reconfigured multiple times a day to create different products. Each time you stop the line to accommodate equipment changeovers, these stoppages waste precious production hours and make it difficult to hit deadlines. What could appear to be minor delays compound every day, resulting in rising costs that eat into your profits. 

Luckily, there’s a proven methodology for reducing equipment downtime and ensuring faster changeovers: single-minute exchange of die (SMED). But what is SMED, why does it matter, and how can it revolutionize your operational efficiency? Follow along for everything you need to know. 

What Is SMED?

SMED is a lean manufacturing system crafted by Shigeo Shingo that prioritizes reducing the amount of changeover time between production runs. Manufacturers can leverage quick changeovers to meet consistent output standards and handle fluctuating customer demand more effectively.

A core tenant of the SMED system is recognizing which processes can be performed while equipment continues to run (external elements) and which ones require machines to be inactive (internal elements). Understanding this distinction and limiting internal elements is foundational to making the manufacturing process faster and more cost-effective.

Key Goals of SMED

One major objective of SMED implementation is to aim for a changeover time that falls within single-digit minutes (less than 10 minutes) to make your production time faster and more flexible. By prioritizing key processes required during the transition, team members can quickly swap out dies, jigs or materials without hindering other operations. 

Another critical component is the identification and elimination of unnecessary steps like redundant checks or inefficient inventory retrieval, which can extend setup times. Here are a few key goals to strive for when enhancing and simplifying your processes using SMED:

• A decrease in wasted motion
• Reduced costs
• Increased production efficiency

Your organization can strengthen its output, quality and delivery standards by focusing on having fully optimized manufacturing systems in which teams prioritize smooth, effective communication and continued improvement.

3 Stages of SMED

Integrating the Single-Minute Exchange of Die method is typically a three-stage process made up of these components: separate, convert and streamline.

1. Separate

Start by creating comprehensive documentation about every step in your current setup and the amount of time each task takes. This analysis allows you to recognize which activities are internal versus external elements.

Internal elements are procedures that require machinery to be turned off. Examples include switching out tooling or adjusting dies. External elements, however, can be done while machines are still operational. Examples include gathering required materials or preparing replacement parts. By distinguishing between these categories, you can schedule tasks so that they are happening at the right time and place.

2. Convert

At this stage, you prioritize shifting as many internal activities as possible to external ones. For example, taking action to pre-stage tools, materials and fixtures ahead of time before the current operation is finished ensures that you won’t need to pause machinery in the next operation. 

You can reduce the amount of time a machine needs to be stopped by proactively shifting your internal activities, for a quicker, more efficient changeover and a substantial reduction in total setup time.

3. Streamline

The final stage focuses on further enhancing efficiency for both internal and external elements. Standardizing your procedures, cutting redundant motions and upgrading to user-friendly tooling are effective strategies for streamlining. 

The ultimate objective is to reduce setup times systematically without sacrificing quality and maintenance safety. Manufacturers can remain agile and responsive to promote continued operational excellence by continuously refining your processes and providing ongoing training.

Benefits of SMED

SMED isn’t solely about reducing changeover times; it sets the tone for a more efficient and fast-paced production environment across the board, resulting in:

• Reduced downtime: The amount of equipment idle time is reduced drastically when internal and external setup tasks are identified and improved upon. Proactively performing previous internal activities before operations begin can ensure the changeover process occurs in less than 10 minutes. This key optimization boosts outputs while ensuring that valuable resources are being used optimally.
• Improved overall equipment effectiveness (OEE): OEE naturally improves when machines spend less time idle. SMED drastically reduces lost production hours caused by lengthy changeover times, increasing the percentage of time that machines are running as scheduled, leading to improved performance and higher-quality outputs over time.
• More production flexibility: Quicker setup times allow manufacturers to better adjust to fluctuations in production demand. An SMED approach allows for producing smaller batches without reducing efficiency, to meet customer needs and market shifts without disruption, even with limited lead time.
• Cost savings: As operational speed improves and downtime is reduced, SMED can significantly lower manufacturing costs and boost profitability thanks to reduced inventory requirements, fewer wasted materials and the means to adjust quickly to new orders 

SMED Example

Imagine one of Toyota’s manufacturing facilities that produces different models of cars on the same production line. The production process requires frequent changeovers between car models, and these changeovers currently take a long time, causing downtime and inefficiencies. The plant wants to reduce these changeover times to increase productivity and flexibility. It takes the following steps to try to achieve this:

1. Process documenting: Map out the entire setup process for switching from one model to another. This includes activities like tool changes, fixture adjustments, part replacements and system recalibration.
2. Separate internal and external elements: Define which activities can be done while machines are running and which ones cannot.
3. Convert internal to external: In the case of the automotive assembly line, the team looks for tasks that are currently done while the machine is stopped and figures out how to do them without requiring machine downtime. For instance, they could pre-assemble parts or set up tools while the current model is still being assembled.
4. Streamline the internal setup: The team might replace bulky, manual tools with quick-change tools that can be swapped more quickly during the changeover process. They may also use standardized parts that can be swapped with minimal adjustment.
5. Standardize the process: This might involve creating standard operating procedures or training employees to perform tasks in a consistent manner.
6. Monitor and continuously improve: After implementing SMED, the plant continues to monitor the setup times and looks for additional opportunities to reduce the time further. They might conduct regular reviews to identify any new bottlenecks or inefficiencies with responsiveness.

Using a CMMS to Improve SMED

A computerized maintenance management system (CMMS) like Coast can be a powerful ally when putting SMED principles into practice. Manufacturers can streamline changeovers and approach single-minute exchange of dies by leveraging the software’s features to optimize maintenance processes and asset performance. Here are several ways a CMMS can help:

• Track and analyze setup times: With real-time maintenance reporting, Coast continuously monitors setup durations and records every step of the changeover process. This data is accessible in a simplified analytics dashboard to highlight recurring issues and bottlenecks, identify patterns and provide insights into which activities can shift from internal to external and where waste can be reduced.
• Improve inventory management: Have the right parts and materials accessible to ensure fast changeovers. Coast’s parts inventory management system tracks stock levels, schedules timely reorders and flags shortages to prevent production shortages.
• Facilitate automated scheduling: Coordinate preventive maintenance tasks and standardize procedures with simplified digital work orders to reduce the risk of unplanned downtime. Perform regular inspections and timely repairs to keep machines operational for the next product run.
• Foster continuous improvement: Integrating simplified data reporting and real-time system monitoring within one platform establishes the feedback loop needed for ongoing refinement of SMED processes. As your teams gain more insights and control, they can continuously enhance efficiency across operations.

Don’t wait to refine your operating procedures with SMED. Get started with Coast for free today.