SMED explained: Reduce changeover time and boost efficiency

Within the Toyota Production System, Shigeo Shingo developed SMED (Single-Minute Exchange of Die), a methodology designed to significantly reduce setup times and make small-batch production viable. The fundamental principle of SMED, which is to minimize changeover times, remains one of the cornerstones of operational flexibility, flow, and efficiency.

This article outlines the fundamentals of SMED, its main operational benefits, and the five key steps for its practical implementation. It also highlights best practices and how this methodology aligns with other continuous improvement approaches.

What Is SMED (Single Minute Exchange of Die)?

SMED, the acronym for Single-Minute Exchange of Die, is a methodology developed to reduce product changeover times on equipment or at workstations along a production line. The term “single-minute” refers to the goal of completing setups in less than 10 minutes. This approach aims to reduce changeover times and batch sizes, thereby improving service levels while minimizing inventory.

Origin and definition of SMED

The SMED concept was developed by Shigeo Shingo, an industrial engineer and consultant at Toyota. In the 1950s, Toyota faced a major challenge: changeovers on stamping presses could take up to four hours. These long setup times made small-batch production unfeasible and hindered the implementation of the Just-in-Time system (JIT) Taiichi Ohno was striving to establish. In response, Ohno challenged his team, directly supported by Shingo, to drastically reduce setup times, thereby making the system more flexible and efficient. This challenge marked the beginning of the development of the SMED methodology.

Figure 1 – Machine efficiency over time

Shingo documented this work in several publications, including A Revolution in Manufacturing: The SMED System, where he detailed the methodology’s principles and its benefits across various production environments. His contributions were internationally recognized, and Utah State University established the Shingo Prize in his honor, which recognizes organizations of operational excellence worldwide.

SMED goes beyond the physical exchange of dies or tools. It encompasses all activities between the last good unit of the previous batch and the first good unit of the next batch—such as stoppages, adjustments, cleaning, and preparation. When applied systematically, the methodology transforms lengthy changeovers into rapid, efficient setups, enhancing agility, efficiency, and industrial competitiveness.

Why “single-minute” matters for changeover time reduction

The term “single-minute” is directly linked to the origins of SMED. Shingo’s goal was to reduce press changeover times at Toyota to under 10 minutes. This symbolic target set a clear, ambitious benchmark that challenged traditional practices and encouraged a shift of mentality in industrial operations.

More than a fixed target, “single-minute” serves as a strategic reference point, motivating teams to strive for shorter changeover times continually. In practice, the actual setup time can often be less than 10 minutes, depending on process complexity, equipment type, and the organization’s operational maturity. In many cases, setups can be reduced to just a few minutes or even seconds.

Benefits for OEE, flexibility, and flow

Implementing SMED improves OEE (Overall Equipment Effectiveness), as well as production flexibility and material flow. Reducing changeover time directly enhances equipment availability. By shortening reference changeover times through the reorganization of work and the elimination of waste, SMED enables increased capacity without the need for additional equipment, thereby avoiding capital expenditures (CAPEX).

But the benefits of SMED go beyond OEE. SMED plays a crucial role in enabling small-batch production, reducing the dependency on large volumes to justify long changeovers. This supports lower inventory levels and greater responsiveness to demand fluctuations.

In this context, the Economic Order Quantity (EOQ) model becomes particularly relevant. EOQ calculates the optimal order size by minimizing the total cost of inventory and ordering. Inventory costs refer to storage and holding costs, while ordering costs relate to the downtime of equipment during the setup process.

Figure 2 – Economic order quantity

Ohno recognized that ordering costs are neither fixed nor constant—they can be reduced by lowering setup times. The result is a reduction in EOQ and decreased inventory costs.

Ultimately, Ohno aimed for “zero changeover,” a scenario in which changeover times are so short that the ideal batch size approaches a single unit, enabling true one-piece flow and production leveling.

For these reasons, SMED is consistently identified as a top-priority initiative during Value Stream Mapping and Design exercises. It is one of the most frequently recommended workshops for improving flow and operational efficiency.

5 SMED steps to reduce changeover time

The SMED method aims to reduce setup time, defined as the interval between the last good unit of the previous batch and the first good unit of the next batch. This reduction extends beyond the physical replacement of tools or dies, encompassing all activities performed while the machine is either stopped or running at low speed. By applying SMED’s five steps, organizations can significantly reduce changeover times—often without any additional equipment investment.

Figure 3 – SMED methodology steps

1. Study the current situation

The first step is to fully understand the current changeover process. This involves observing the existing setup method with input from the team responsible for its execution. Key activities carried out include:

• Filming the entire setup process for each operator from start to finish.
• Creating a Spaghetti Diagram to visualize operator movements and highlight unnecessary movements.
• Timing each task recorded in the videos.
• Entering data into a spreadsheet, organizing tasks in chronological sequence, and by operator.
• Categorizing each task as:
  • Internal work: Tasks that can only be performed while the machine is stopped.
  • External work: tasks that can be performed while the machine is running.
• Identifying waste such as waiting, movements, searching for tools, or duplicate tasks.
• Calculating total changeover time and the subtotals per task.
• Listing all tools and materials required for each task.

This detailed diagnosis serves as the basis for the subsequent steps.

2. Separate internal work from external work

After conducting a detailed task analysis with the operators’ input, it’s essential to reorganize all setup tasks based on their operational nature (internal or external). This separation is the starting point for reducing machine downtime. The main activities are:

• Defining the optimal task sequence, clearly dividing tasks into three distinct groups:
  • External work to be completed before the machine stops.
  • Internal work that requires the machine to be stopped.
  • External work to be completed after the machine restarts.

This initial reorganization alone can lead to significant improvements and sets the stage for the next steps—converting internal tasks into external ones and streamlining the entire process.

3. Convert internal tasks to external tasks

Once internal (machine-stopped) and external (machine-running) work has been clearly separated, the next step is to convert as many internal tasks as possible into external ones. The goal is to anticipate or postpone all activities that don’t rely directly on the machine being stopped, enabling them to be performed while the machine is still running or has already resumed operation. This conversion significantly reduces effective downtime.

This step involves modifying work methods, introducing technical improvements, or reorganizing tasks so they fall outside the machine’s critical downtime. Practical examples include:

• Preheating molds or tools: Heating components to ensure immediate readiness at optimal temperature.
• Standardizing mold height: Adapting the support bases to eliminate the need for height adjustments during installation.
• Pre-assembling components: Preparing auxiliary parts outside the machine before the setup begins.

Converting internal tasks to external ones is a crucial step in reducing downtime and enhancing equipment availability.

4. Streamline all remaining internal activities

After converting as many tasks as possible, the next SMED step is to reduce or eliminate the time and effort associated with internal activities that cannot be avoided. The goal is to execute these tasks as quickly, safely, and efficiently as possible.

Streamlining internal setups involves standardizing procedures, eliminating manual adjustments, and implementing technical and organizational solutions to reduce variability and waste.

Practical examples include:

• Fastening and quick connections: Replacing screws with levers, clamps, or snap-in connections to avoid the use of tools.
• Automatic clamping systems: Using pneumatic or hydraulic systems to reduce time and human effort.
• Mutual support tasks: Having two operators perform tasks simultaneously to shorten overall downtime.
• Tool duplication and preparation: Using pre-calibrated, pre-positioned, or duplicate tools to eliminate setup adjustments.
• Guided transport and positioning: Implementing tracks, stoppers, or alignment systems to prevent errors and speed up setup.
• Color codes and visual standards: Using visual cues for easy identification and alignment with standardized visual elements.
• Replace electrical connections: Bundling cables into single connectors to reduce connection/disconnection time and errors.
• Dedicated setup and cleaning kits: Ensuring all necessary materials are organized, prepared, and accessible at the start of the setup.

Streamlining internal activities ensures that setup times are not only reduced but also predictable and standardized, eliminating variations, errors, and waste.

5. Reduce external work

Although the external setup does not directly impact machine downtime, it still consumes valuable resources. Improving these tasks contributes to overall process efficiency by reducing waste and preparation time. Strategies for optimizing or reducing external work include:

• Simplifying or reducing transport and movement during setup by placing tools and materials closer to the point of use.
• Improving the design, organization, and accessibility of tools and accessories using dedicated cabinets, shadow boards, visual management, and visual location systems.
• Implementing 5S practices in support areas and workstations to maintain clean, organized, and standardized environments.

Even if external work doesn’t affect machine downtime, it consumes valuable resources.

Figure 4 – Evolution through the 5 SMED steps

Good practices in the implementation of SMED

When applying the SMED method, it’s essential to adopt good practices that ensure both the effectiveness of implementation and the sustainability of results. These practices reinforce gains achieved at each stage, guarantee the standardization of the new setup method, and reduce the risk of regression, even with team, shift, or product changes.

Standardize the process and create a SMED checklist

The ultimate goal of SMED is to establish an improved work method that can be consistently repeated. Standardization ensures that the time-saving benefits of reduced setup times are sustained over time, regardless of which team or shift is performing the changeover.

Standardizing the setup involves developing a precise operational sequence that details every internal and external task—when is done, by whom, and with which tools. It is strongly recommended to develop simple, intuitive visual checklists and display them at workstations. Training operators on the new standardized sequence is also crucial. This provides a solid foundation for continuous improvement.

Implement quick-release and poka-yoke tools

One of the most effective ways to reduce setup time and complexity is by replacing conventional fastening and connection systems with quick-release tools and poka-yoke devices (error-proofing mechanisms). These solutions accelerate the process, ensure repeatability, and reduce reliance on individual operator experience.

Quick-release tools enable components to be secured and released quickly and safely, without the need for additional tools. Practical examples include:

• Hydraulic or pneumatic clamping systems activated by button or foot pedal – eliminate manual effort and improve repeatability.
• Base plates with locating pins – enable automatic positioning of molds and fixtures without the need for adjustment.
• Cam levers – replace screws and wrenches with quick lever-action fastening.
• Quick-change rails with sliding blocks – allow easy tool swaps with minimal operator intervention.

Poka-yoke devices are mechanisms designed to prevent errors during setup, ensuring each task is performed correctly by default. Common examples include:

• Asymmetric alignment guides – prevent inverted installation of molds, plates, or fixtures.
• Shape-coded connectors – prevent incorrect electrical or pneumatic connections.
• RFID or QR Code readers – automatically verify that the correct tool is installed for the product in production.
• Presence and position sensors – block machine start-up if components are misaligned.
• Captive screws or nuts – eliminate the risk of loose parts, losses, or incorrect assembly.

Combining quick-release tools with poka-yoke devices not only speeds up setup but also enhances safety, reduces errors, and strengthens process standardization—even in high-turnover environments or with a high variety of products.

Introduce parallel operations & pit-stop choreography

To achieve highly efficient setups, tasks should be distributed in a synchronized way among multiple operators, allowing them to work in parallel rather than sequentially. This approach, inspired by Formula 1 pit crews, is known as pit-stop choreography. This practice involves:

• Clearly divided responsibilities for each operator.
• Simultaneous execution of tasks whenever possible.
• Structured team training and rehearsal until the process flows seamlessly.
• Visual or signal coordination to ensure operators act at the right time without interfering with one another.

Key benefits include:

• Significant reduction in total setup time.
• Greater process consistency and repeatability.
• Enhanced team collaboration.

Parallel operations turn a time-consuming, linear setup into an agile, collaborative, and highly efficient process—ideal for environments that demand high flexibility and rapid change.

Optimize with OTED for single-touch changeovers

OTED (One-Touch Exchange of Die) is an advanced extension of the SMED methodology, aiming to achieve setups that require only one movement or a simple gesture, usually completed in under one minute. This concept takes the quick-change principle to its most extreme level, focusing on automation, total standardization, and technical integration.

Key features of an OTED setup include:

• Changeover is performed with a single touch—via a lever, button, or command.
• No need for manual adjustments, alignments, or additional tools.
• The process is entirely predictable, repeatable, and safe.
• Machine downtime is practically zero.

Practical examples of OTED include:

• Molds with automatic alignment and hydraulic clamping.
• Robotic tool-changing systems.
• Equipment with electronic pre-configuration of production parameters.
• Modular devices with guided and quick-connect interfaces.

OTED is typically implemented in environments with very high setup frequency, where downtime carries a significant financial impact, and on production lines with a high degree of automation.

Although OTED requires more substantial technical investment, the benefits—in terms of time savings, increased flexibility, and improved operational efficiency—can fully justify the investment, especially in high-demand, high-variability contexts.

Digital tools & software for SMED implementation

Successfully implementing SMED requires not only a structured approach but also the support of digital tools that help sustain and scale improvements over time. From digital solutions to information systems, each resource should contribute to reducing changeover times and standardizing setup-related activities.

Comparing leading SMED software (Excel, cloud, SaaS)

The analysis and planning of SMED events can be greatly enhanced by digital tools that allow teams to monitor data, compare setup performance, and identify improvement opportunities more accurately.

Commonly used options include:

• Excel templates – Suitable for simpler environments, Excel offers flexible, low-cost options for mapping activities, recording time, and generating basic analysis charts.
• Cloud-based or SaaS software – More advanced Lean-focused platforms provide advanced features such as:
  • Synchronized video analysis with task timelines.
  • Interactive schedules and real-time dashboards.
  • Centralized management of setup checklists and standards.
  • Integration with MES or ERP systems for continuous monitoring.

These features make the SMED process more collaborative, visual, and consistent, even in complex manufacturing environments with multiple shifts or distributed production sites.

Digital work instructions and IoT feedback loops

Digitizing work instructions is an increasingly adopted practice to ensure standardized, visual, and error-free execution of setup procedures. Using tablets, digital panels, or MES (Manufacturing Execution Systems), operators can access:

• Step-by-step multimedia guides (text, images, video).
• Interactive checklists with real-time validation.
• Automatic alerts for deviations from standard procedures.

When these instructions are integrated with IoT technology, real-time feedback loops can be established, enabling automated data collection directly from the equipment. This allows:

• Monitoring of actual setup times.
• Detection of anomalies and variability between shifts or operators.
• Early identification of maintenance needs.
• Promote immediate corrective actions based on objective data.

This approach makes SMED implementation more resilient and data-driven, aligning it with Industry 4.0 principles and enhancing the stability of continuous improvement and long-term results.

Calculating & tracking SMED KPIs and ROI

Measuring the outcomes of SMED implementation is essential to validate the improvements achieved and support ongoing continuous improvement efforts. Monitoring key performance indicators allows teams to quantify the effectiveness of implemented actions, identify new opportunities, and justify investments with real data. Additionally, it provides operational visibility to both teams and management, reinforcing the organization’s commitment to operational excellence.

Create key metrics

Ongoing monitoring is critical to ensure that improvements achieved through SMED are sustained over time. The most relevant indicators are the average changeover time, including both internal and external work, as well as the variability of changeover times. Consistently monitoring these metrics enables teams to quickly identify deviations from the standard and take corrective action, thereby maintaining process stability and effectiveness.

To ensure effective tracking, certain routines must be standardized:

• Results should be recorded every time a setup is performed, promoting direct team accountability.
• Setup times should be logged in a simple and visible way, ideally using visual boards at team workstations.
• Any problems or anomalies observed during setup should be recorded and collectively reviewed to facilitate resolution.
• Deviations from target time should be analyzed in a structured team setting, focusing on identifying root causes and defining countermeasures.
• The standard operating procedure should be reviewed regularly by the team to ensure it remains appropriate, safe, and effective.

When these metrics are combined with direct shop-floor observation and active operator involvement, they become a powerful tool for collective learning, standard reinforcement, and risk mitigation against regression.

How to calculate the impact of SMED

Evaluating the impact of SMED must go beyond simply measuring setup time. A comprehensive analysis must quantify both direct and indirect operational gains across indicators relevant to production efficiency and strategic decision-making. Examples of performance metrics include:

• Overall equipment efficiency: The gain in availability improves the OEE, especially in contexts with frequent setups.
• Number of setups per shift or day: With reduced setup time, it becomes possible to perform more changeovers without sacrificing output, enabling smaller batch sizes and greater product variety.
• Inventory reduction and associated cost savings: Faster setups allow production to align more closely with demand, decreasing the need for stockpiling.
• Response time and flexibility: The ability to switch products quickly improves customer responsiveness and supports faster adaptation to demand fluctuations.
• Financial impact and ROI: Financial gains can be quantified by evaluating the reduction in non-productive time, increased available capacity, and lower inventory-related costs.

By measuring not just the reduction in setup time but also its effect on key operational metrics, the actual value of SMED becomes evident—not as a one-time improvement, but as a strategic enabler of efficiency, flexibility, and competitive advantage.

Integrating SMED with Kaizen, TPM & Six Sigma

The SMED methodology should not be seen as a standalone initiative but rather as a tool embedded within a broader ecosystem of operational excellence. Its application is often combined with structured approaches such as Kaizen, TPM (Total Productive Maintenance), and Six Sigma, which promote continuous improvement and sustained waste reduction.

Connection between 5S and SMED

The 5S methodology lays the groundwork for effective SMED execution. By fostering workplace organization, visual standardization, and operational discipline, 5S supports fast, safe, and repeatable setups.

• Sort (Seiri) helps eliminate unnecessary tools and materials, reducing clutter and confusion during changeovers.
• Straighten (Seiton) ensures essential items are always in the right place, ready for immediate use.
• Scrub (Seiso) makes it easier to detect anomalies that could affect quality after a setup.
• Standardize (Seiketsu) ensures that all team members follow the same process, minimizing variability.
• Sustain (Shitsuke) reinforces consistent execution of setup standards.

5S not only enables effective SMED but also supports the long-term sustainability of its results.

Embedding SMED in TPM pillars

TPM focuses on maximizing equipment efficiency and involving operators directly in maintenance and improvement. SMED integrates seamlessly into several TPM pillars:

• Targeted improvement: SMED is a core tool for eliminating setup-related losses.
• Autonomous maintenance: Operators who are trained in basic equipment care can perform setups more effectively, detect issues early, and carry out minor adjustments.
• Training and skill development: SMED training enhances team autonomy and versatility.

By embedding SMED into the pillars, organizations strengthen operational stability and foster a culture of shared responsibility.

Including SMED in Gemba Walks

Gemba Walks are routine, structured visits to the shop floor, a Japanese term meaning “the place where work happens”. In this context, leaders observe processes firsthand, engage with employees, check for standard compliance, and drive continuous improvement. Ideally, they should involve leaders from all levels—from supervisors to top management—focusing on active listening and team respect.

In the context of SMED, Gemba Walks are a powerful tool for:

• Verifying compliance with the setup operating mode to ensure that the defined standards are being applied correctly.
• Identifying deviations, inefficiencies, or waste during changeovers.
• Reinforcing desired behaviors.
• Involving operators in improvement.

Consistent leadership presence on the floor sends a clear message: operational excellence is a shared priority. It also provides visibility to best practices, acknowledges team efforts, and helps sustain improvements over time.

Overcoming operator resistance through Kaizen Blitz facilitation

Changes to work methods often generate resistance, especially if operators aren’t involved from the beginning. Kaizen Blitz (or Kaizen workshops)— focused, rapid improvement—are a highly effective way to overcome this resistance and foster active engagement.

During these workshops, teams:

• Observe and analyze real setups.
• Participate in redesigning the setup procedure.
• Test new practices in real time.
• Assist in creating new setup standards and checklists.

This direct involvement builds ownership, trust, and acceptance of the new process. It also increases commitment to execution, ensuring that improvements become part of the daily routine and are sustained over time.

Still have some questions about SMED?

Can SMED be integrated with digital transformation?

SMED can and should be integrated into digital transformation initiatives. Its effectiveness can be significantly enhanced through technologies such as IoT sensors, video analysis, real-time monitoring software, digital work instructions, and MES systems. These tools enable the reliable collection of setup data, help identify process variations, reinforce standardization, and promote continuous improvement based on structured information.

What does “single-minute” mean in SMED?

In the context of SMED, the term “single-minute” refers to the goal of reducing tool or setup changeover time to fewer than 10 minutes—that is, a single-digit number of minutes. This target represents a challenging performance benchmark that encourages teams to rethink traditional methods, eliminate waste, simplify tasks, and boost operational efficiency.

Is SMED only applicable to manufacturing?

While SMED was initially developed for the manufacturing industry, its principles are widely applicable to any environment where there are changeovers, configuration shifts, or task preparations. This includes sectors such as logistics, healthcare, retail, and administrative services, where SMED can be used to reduce setup or transition times, improve productivity, and enhance responsiveness across workflows.