Imagine a pit stop in a Formula 1 race: seconds shaved off tire changes can mean the difference between victory and defeat. In manufacturing, that “pit stop” is the setup time, and SMED (Single-Minute Exchange of Dies) is the technique that revolutionizes it. This article explores SMED, a powerful methodology for anyone involved in manufacturing, process improvement, or lean management, who aims to drastically reduce changeover times and boost overall efficiency.

Main Takeaways From This Article:

  • SMED is a methodology aimed at reducing equipment changeover times to under 10 minutes, significantly minimizing downtime and improving production efficiency.
  • Waste Reduction and Lean Manufacturing: SMED plays a crucial role in Lean manufacturing by eliminating waste associated with lengthy changeovers. This includes reducing idle time, unnecessary motion, and excess inventory, leading to cost savings and increased profitability.
  • Enhanced Production Agility: By enabling faster changeovers, SMED allows for smaller batch production and Just-in-Time (JIT) manufacturing. This increases a company’s ability to respond quickly to market demands and reduces the need for large inventories.
  • Process Optimization and Standardization: The SMED process involves a systematic approach to identifying, separating, converting, and streamlining changeover elements. This includes using techniques like video recording and detailed analysis to optimize each step and standardize procedures.
  • Human and Technical Integration: Successful SMED implementation requires a combination of technical improvements (e.g., quick-release fasteners) and human factors (e.g., operator training and standardized work instructions).

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

Single-minute exchange of dies (SMED) is a process used to reduce the time it takes to complete equipment changeovers. The term “single-minute” is a bit misleading—it doesn’t mean every changeover should only take one minute, but that every changeover should take less than 10 minutes, or a single-digit minute.

What is Changeover?

In most manufacturing environments, you’ll find machines that are designed to perform more than just one task. Perhaps there’s a drill press that is used to drill holes in the top of a part, and then is tilted in order to drill horizontal holes in the side.

The process of moving the drill from vertical to horizontal is called changeover. Depending on the size and complexity of the machine, the experience of the operator, and the process used during changeover, the time consumed during changeover is considered downtime—everything else is waiting on the machine to resume functioning.

How the Changeover Process Can Lead To Waste

To the Lean organization, waiting and downtime are wasteful and countermeasures need to be in place to keep waiting at a minimum during the changeover period. And in any business, one of the heaviest drains on profitability is waste.

Lean waste can come in the form of time, material, and labor. But it may also be related to the utilization of skill sets as well as poor planning. In lean manufacturing, waste is any expense or effort that is expended but which does not transform raw materials into an item the customer is willing to pay for.

By optimizing process steps and eliminating waste, only true value is added at each phase of production.

The Origins of SMED and Its Role in Lean Manufacturing

Shigeo Shingo, working at Toyota decades ago, recognized the immense waste caused by lengthy machine changeovers. Witnessing production lines halted for hours, even days, due to die changes on massive stamping machines, he sought to eliminate this downtime. This frustration led him to develop the Single-Minute Exchange of Die (SMED) system.

SMED is a set of techniques designed to reduce equipment setup and changeover times to under 10 minutes, operating within the “single-minute” range. Shingo’s methods dramatically shortened changeover durations, with documented reductions averaging 94% across various industries, transforming lengthy processes into swift, efficient operations and solidifying SMED’s crucial role in lean manufacturing.

The SMED Process

In an SMED process, changeovers are comprised of steps or “elements.” There are two types of elements: internal and external.

  • Internal elements must be completed when the equipment is stopped.
  • External elements can be completed while the equipment is running.

The main goal of the SMED process is to have as many external elements as possible while streamlining and simplifying all other elements. Changeover times that improve by a factor of 20 may be hard to imagine, but consider the simple example of changing a tire:

  • For many people, changing a single tire can easily take 15 minutes.
  • For a Formula One pit crew, changing four tires takes less than 5 seconds.

Many techniques used by NASCAR and F1 pit crews (performing as many steps as possible before the pit stop begins; using a coordinated team to perform multiple steps in parallel; creating a standardized and highly optimized process) are also used in SMED. In fact, the journey from a 15-minute tire changeover to a 5-second tire changeover can be considered a SMED journey.

Steps to Implement SMED for Faster Changeovers

Implementing Single-Minute Exchange of Dies (SMED) can dramatically reduce changeover times, but it requires a structured approach. Here’s a concise overview of the key steps involved in successfully implementing SMED for faster changeovers:

1. Identify a Test Area

One of the first things to consider before implementing SMED is the pilot or test area. Choose to work on only one machine or one area. In this step, it’s important to get everyone onboard with the SMED implementation—this includes all employees associated with the selection process and those who will work on the changeover.

2. Identify Elements

After you’ve determined your pilot area, it’s time to work together with your SMED team to identify all the changeover elements—internal and external.

One of the most effective ways to visualize every step is by video recording an entire changeover as it is currently performed, and then sitting down with your team to record lists of each element, reordering as needed.

Include a detailed description of each task performed and how long each task takes to complete (cost in time). This video and outline can also serve as a baseline. Once step two is finished, you should have a complete list of all changeover elements with a description and cost in time for each.

3. Separate External Elements

Can this element be performed while the machine is running? This is the question your team needs to ask of each element you documented in the previous step. Any element in the changeover process that can be completed with little or no change while the machine is in operation must be identified and labeled as “external” to the process—in other words, the element can be done before or after the changeover.

In many cases, this step alone can cut changeover time in half. Once step three is completed, you should have an updated list of changeover elements divided into external elements (before changeover), internal elements (during changeover) and external elements (after changeover).

4. Convert Internal Elements to External Elements

Which internal elements can be converted to external elements? This question should be at the forefront of everyone’s mind as you go through the changeover process with a fine-tooth comb. Breaking down the question even further, your team might ask: If there is a way to make this element external, what would it be and how can we do it?

What’s left after this evaluation is a list of elements that require further action. Prioritize this list so the elements with the most promising results are dealt with first. In other words, perform a cost/benefit analysis on each element from the list.

5. Streamline Remaining Elements

How can this element be done in less time? Or, how can we simplify this element? Finally, your SMED team should review the remaining elements on your list. Focus on simplifying them so they can be done in less time. Since the goal is to reduce changeover time, give priority to internal elements before moving onto the external. Use a cost/benefit analysis to prioritize the remaining steps. Once step five is completed, update your standardized work instructions for the changeover.

Human vs. Technical Aspects of Changeovers

SMED’s success hinges on a dual approach, addressing both the technical and human aspects of changeovers. The technical side focuses on process optimization, involving engineering solutions like quick-release fasteners or pre-setting tools to minimize downtime. Conversely, the human element emphasizes operator engagement, requiring training, standardized procedures, and fostering a culture of collaboration to ensure efficient execution. For example, while engineers might redesign equipment for faster die changes (technical), operators must be trained to follow precise, standardized steps during the process (human), ensuring both speed and accuracy.

Benefits of SMED in Lean Manufacturing

The SMED methodology acts as a powerful catalyst within Lean manufacturing, driving efficiency and profitability. By systematically reducing changeover times, it unlocks a cascade of benefits that reshape production dynamics.

Minimizing Equipment Idle Time

SMED directly combats unproductive downtime by accelerating changeovers, thereby maximizing the operational lifespan of machinery. Imagine a manufacturing plant where reducing a two-hour setup to fifteen minutes significantly amplifies daily production output. This optimization of machine utilization is crucial for boosting Overall Equipment Effectiveness (OEE).

Eliminating Extraneous Motion and Waste

SMED meticulously streamlines workflows, purging non-essential activities like tool searches or idle waiting periods. This focus on eliminating waste and unnecessary movement enhances operational efficiency and reduces cycle times, aligning perfectly with Lean’s core principle of maximizing value while minimizing waste. For instance, pre-positioning tools and materials adjacent to the machine eliminates wasted motion.

Enhancing Production Agility and Responsiveness

SMED empowers manufacturers to rapidly adapt to shifting market demands by facilitating swift changeovers. This agility enables smaller, more frequent production runs, reducing reliance on extensive inventory and improving responsiveness to customer needs. A company producing seasonal goods can swiftly reconfigure its production lines to match fluctuating demand.

Facilitating Smaller Batch Production and JIT Manufacturing

By enabling smaller batch sizes and reducing inventory, SMED optimizes production scheduling and supports Just-in-Time (JIT) manufacturing. This minimizes storage costs and obsolescence risks, promoting a more efficient and responsive production model. An automotive factory using SMED can produce various car models in smaller batches, catering to specific customer orders and reducing storage.

Reducing Overall Manufacturing Expenditures

SMED significantly reduces manufacturing costs by minimizing downtime, excess inventory, and waste. Reduced setup times translate to more productive hours, while lower inventory levels decrease storage expenses and obsolescence risks. This efficiency directly impacts the bottom line, making SMED a crucial tool for cost-conscious manufacturers.

Improving Workplace Safety and Organization

Standardizing changeover procedures enhances workplace organization and safety by establishing clear, repeatable processes. Well-organized workspaces and standardized procedures minimize accident risks and errors, fostering a safer and more efficient work environment. For example, designated storage for changeover tools reduces tripping hazards.

Integrating Human and Technical Efficiencies

SMED harmonizes workforce efficiency with technical process optimization to ensure seamless and rapid changeovers. By combining operator training and standardized workflows with engineering improvements to machinery, SMED creates a comprehensive approach that maximizes efficiency. This balance ensures that both human and machine resources operate in synergy for optimal performance.

Optimize Lean Manufacturing with KPI Fire for Continuous Improvement

By fundamentally altering changeover dynamics, SMED unlocks significant efficiency gains within Lean manufacturing environments. This methodology allows for the dramatic reduction of setup times, the systematic elimination of process waste, and a substantial increase in overall operational effectiveness. Consequently, manufacturers experience heightened production agility, enabling swift responses to market fluctuations and the implementation of smaller, more frequent production batches. This shift directly translates to decreased inventory holdings and reduced downtime, leading to significant cost savings and amplified productivity. Essentially, SMED reshapes manufacturing into a more adaptable, economical, and highly responsive system.

The true value of SMED, however, extends beyond initial implementation. Consistent and enduring benefits necessitate a commitment to continuous refinement, involving diligent performance monitoring, stringent accountability measures, and relentless process optimization. To achieve sustained success, organizations must actively track progress and implement data-driven adjustments.

KPI Fire serves as a pivotal tool in this endeavor. By aligning Lean and strategic initiatives, including SMED, with overarching strategic objectives, it provides real-time performance insights and facilitates ongoing improvement. This platform empowers organizations to maintain the momentum of their SMED efforts, ensuring lasting efficiency and profitability. Request a demo today to discover how KPI Fire can revolutionize your changeover process and foster continuous improvement.