In the competitive world of manufacturing and operations, efficiency and agility are more crucial than ever. Reducing downtime, optimizing processes, and quickly responding to changing market demands are key objectives for any organization seeking excellence. This is where Single Minute Exchange of Die (SMED), or “Quick Tooling Change in Single-Digit Minutes,” emerges as a fundamental lean methodology.
Have you ever wondered how some companies manage to switch from producing one product to another in a matter of minutes, while others take hours or even days? The answer often lies in the effective implementation of SMED. This comprehensive article will explore in depth what Single Minute Exchange of Die is, its definition, meaning, examples, and how SMED techniques are applied to radically transform productivity.
The urgency of efficiency in changeover times
Machine preparation or “setup” times, the process of switching a production line from one product to another, have historically been a significant bottleneck in manufacturing. Prolonged changeover times lead to a series of problems:
- Lower productive capacity: Machines remain idle for longer periods.
- Larger production batches: To minimize the impact of long changeovers, companies tend to produce in large quantities, which increases inventories.
- Higher work-in-process (WIP) and finished goods inventory: This ties up capital and space.
- Reduced flexibility: Difficulty adapting to small orders or changes in demand.
- Longer delivery times: Impacting customer satisfaction.
- Hidden costs: Related to storage, obsolescence, and inventory handling. Single Minute Exchange of Die (SMED) directly addresses these challenges, aiming to drastically reduce changeover times, ideally to less than ten minutes (hence “single minute” referring to a single-digit number of minutes).
What is Single Minute Exchange of Die (SMED)?
Single Minute Exchange of Die (SMED) is one of the lean production methods designed to reduce waste in a manufacturing process (Hasabe et al., 2019). SMED is used to quickly and efficiently switch a manufacturing process from producing the current product to producing the next product.
The SMED methodology was developed in Japan by Shigeo Shingo, a Toyota consultant, between the 1950s and 1970s. The meaning of Single Minute Exchange of Die lies in its main objective: to reduce the changeover time for tooling (dies, molds, tools, etc.) in machines and production processes to a period expressed in a single-digit number of minutes (i.e., less than 10 minutes).
It is important to clarify that the term “single minute” does not always literally mean 60 seconds, but rather the aspiration to achieve extremely short changeover times. The definition of single minute exchange of die focuses on a set of techniques and principles that enable this drastic reduction. SMED is synonymous with “quick changeover.”
Single Minute Exchange of Die is not limited only to the exchange of “dies” (matrices or molds), but SMED techniques are applied to a wide range of changeover operations in various industries, from manufacturing to services, such as operating room changeovers in hospitals or aircraft preparation between flights.
Origins and history of SMED
Shigeo Shingo conceived Single Minute Exchange of Die (SMED) in the 1950s (Che & Shafei, 2014), while working with Toyota and other Japanese companies. He observed that long changeover times were a significant barrier to achieving the continuous flow and Just-in-Time (JIT) production that Toyota was developing. Shingo’s detailed analysis of changeover processes revealed that many activities could be performed more efficiently or eliminated entirely. A key milestone was the reduction of changeover time for a 1,000-ton press at Toyota from four hours to just three minutes.
The fundamental principles of SMED
The Single Minute Exchange of Die (SMED) methodology is based on several key principles that guide the changeover time reduction process:
- Identify and separate internal and external operations: This is the most crucial concept in SMED (Carrizo & Campos, 2011).
- Internal Operations (Internal Setup): Those that can only be performed when the machine is stopped (e.g., dismounting the old die, mounting the new one).
- External Operations (External Setup): Those that can be performed while the machine is running, producing the previous batch, or preparing for the next one (e.g., fetching tools, preheating molds, preparing materials).
- Convert internal operations to external operations: The goal is to transform as many internal operations as possible into external ones. This directly reduces machine downtime.
- Optimize all operations (internal and external): Once separated and converted, all remaining operations must be analyzed and simplified to reduce the time they consume.
- Eliminate adjustments: Reduce or eliminate the need for fine-tuning after the changeover by using templates, stops, or standardized positioning systems.
- Standardize the changeover process: Create standardized work procedures to ensure consistency and facilitate training.
Key stages for SMED implementation
The implementation of Single Minute Exchange of Die (SMED) generally follows a series of structured stages:
Stage 0: Initial measurement and observation (preliminary phase)
- Analysis of the current process: Observe and meticulously record all activities involved in the current changeover process. It is common to use video recordings for later analysis.
- Baseline time measurement: Determine the total changeover time and the time for each individual activity.
- SMED team formation: Involve a multidisciplinary team (operators, engineers, maintenance personnel) familiar with the process.
Stage 1: Separate internal and external operations
- Identify tasks: Review the list of activities and classify each one as internal or external.
- Create checklists: For external tasks, ensure everything is prepared before the machine stops (tools, materials, instructions, personnel).
- Examples of external tasks: transporting dies, preparing tools, preheating molds, inspecting components.
Stage 2: Convert internal operations to external operations
- Re-evaluate each internal operation: Ask, “Can we do this while the machine is running?” Sundaramali et al. (2024) recommend that internal activities can be converted into external activities by implementing various techniques such as 5S, the Deming principle, and standardization.
- Modify equipment or processes: This may involve redesigning machine parts, using duplicate tooling, or changing the sequence of operations.
- Single minute exchange of die conversion example: If a tool needs to be preheated, and this is done after stopping the machine (internal), it can be changed to preheating it in an external device while the machine is still producing (external).
Stage 3: Optimize all aspects of the changeover operation
This stage focuses on reducing the time of the remaining internal and external operations.
- Optimize the remaining internal operations:
- Implement functional clamping: Replace bolts with quick clamps, levers, or one-touch fastening systems. Eliminate the need for tools whenever possible.
- Eliminate adjustments: Use fixed positioning systems, gauges, or standardized shims to avoid the need for prolonged manual adjustments. Standardize the dimensions of dies and tools.
- Mechanization and automation: Where justifiable, use power tools, lifting systems, or robots for the heaviest or most repetitive tasks.
- Parallel work: Organize tasks so that multiple operators can work simultaneously on different aspects of the changeover without interfering with each other.
- Optimize external operations:
- Workplace organization (5S): Ensure that tools, tooling, and instructions are clearly organized, labeled, and within reach.
- Dedicated tool carts: Prepare carts with everything necessary for a specific changeover.
- Standardization of tools and components: Reduce the variety of tools and fasteners needed.
Stage 4: Document, standardize, and continuously improve
- Create standard operating procedures (SOPs): Document the new, optimized changeover process.
- Train personnel: Ensure that everyone involved understands and follows the new procedures.
- Monitor and measure: Continue measuring changeover times to ensure improvements are sustained.
- Foster continuous improvement (Kaizen): Constantly seek new opportunities to further reduce changeover times.
Key advantages of implementing Single Minute Exchange of Die (SMED)
The successful implementation of Single Minute Exchange of Die (SMED) offers a multitude of benefits that directly impact a company’s profitability and competitiveness:
- Drastic reduction in downtime: Proper SMED implementation can drastically reduce downtime and increase overall equipment efficiency (Che & Shafei, 2014; Godina et al., 2018). This is the most obvious benefit. Less machine downtime means more production time.
- Increased production flexibility: According to Hasabe et al. (2019), Single Minute Exchange of Die (SMED) increases manufacturing flexibility and responsiveness to the demand for a wider variety of products and better quality. In this sense, the methodology allows for producing smaller batches economically, which facilitates adaptation to variable customer demand and product customization.
- Reduced inventory levels: By being able to efficiently produce smaller batches, the need to maintain large work-in-process (WIP) and finished goods inventories is reduced. This frees up capital and storage space.
- Improved quality: Standardized and simplified changeover processes reduce the probability of errors and misalignments, which can lead to a lower defect rate.
- Increased productive capacity: By minimizing time lost in changeovers, the effective capacity of machinery increases without the need to invest in new equipment.
- Faster customer response: The ability to quickly switch between products allows for shorter delivery times; in this regard, it includes an increase in customer service levels (Che & Shafei, 2014).
- Lower production costs: Reduced inventories, a lower defect rate, and overall greater efficiency contribute to a decrease in operating costs.
- Improved employee morale and safety: Simpler, faster, and well-organized changeover processes can reduce operator frustration and physical exertion, improving their satisfaction and safety. Likewise, Nájera et al. (2024) state that the application of Single Minute Exchange of Die (SMED) brings discipline, task analysis, and a better understanding of machinery and worker experience, while also helping to improve their behaviors, indispensable aspects for seeking improvements.
- Facilitates Lean and JIT implementation: SMED is a fundamental pillar for achieving a lean production system and Just-in-Time.
Challenges and considerations in SMED implementation
Although the benefits of Single Minute Exchange of Die (SMED) are significant, its implementation can present certain challenges:
- Resistance to change: As with any improvement initiative, there may be resistance from employees accustomed to old methods.
- Initial investment: Some SMED solutions may require investments in new tooling, machine modifications, or specialized tools. It is crucial to analyze the return on investment.
- Requires management commitment: The support and leadership of top management are essential for the success of the SMED program.
- Need for training and skills: Operators and technical staff may need training in the new techniques and procedures.
- Complexity in certain environments: In industries with very complex or regulated processes, the implementation of Single Minute Exchange of Die (SMED) can be more challenging, but not impossible.
- Not a one-size-fits-all solution: SMED should be seen as part of a broader continuous improvement effort, not as an isolated solution.
Application examples of Single Minute Exchange of Die (SMED)
The most classic single minute exchange of die example comes from the automotive industry, specifically in changing dies in large stamping presses. However, SMED techniques are applied to a vast range of industries and processes:
Manufacturing
- Changing molds in plastic injection molding machines.
- Changing tools in CNC machining centers.
- Adjusting packaging lines for different products or formats.
- Changing rollers in printing presses.
- Preparing textile machines for different fabrics or patterns.
Food industry
Farwaha et al. (2024) revealed that SMED implementation yields positive results even in the food processing industry; for example, in cleaning and reconfiguring processing lines between different food products.
Oil industry
Junior et al. (2022) developed a new single-minute exchange of die (SMED) framework for an oil company and reported a 91.6% improvement in setup time, reducing it from 1 h 44 min 56 s (6296 s) to 8 min 52 s (532 s), and a 44.6% increase in overall equipment effectiveness.
Pharmaceutical industry
Cleaning and preparing equipment for different batches of medications, complying with strict regulations.
Healthcare service
Freitas et al. (2025) investigated the application of the single-minute exchange of die (SMED) system to reduce setup time in an obstetric hospital ward in Feira de Santana, Bahia – Brazil, and concluded that the methodology proved effective in significantly reducing setup times, achieving an average decrease of 20%. On the other hand, SMED can be used, for example, in preparing operating rooms between surgeries.
Automotive industry
Lopes et al. (2024) highlight that the implementation of the SMED methodology in the automotive sector is fundamental to increasing productivity and maintaining competitiveness; similarly, the results of the study by Desai and Rawani (2017) allowed them to conclude that the application of the Single Minute Exchange of Die (SMED) methodology led to a reduction in setup time and tool change time, making it an effective tool that a manufacturing organization can apply to improve its ability to increase customer satisfaction through better utilization of plant assets.
For their part, Singla and Mohan (2024) report that the application of the lean manufacturing principles Single Minute Exchange of Die (SMED) and Kanban in a case study of an automotive emblem manufacturing setup resulted in significant improvements in various productivity metrics.
Specific techniques and common tools in SMED
In addition to the general principles and stages, there are more specific techniques and tools frequently used in Single Minute Exchange of Die – SMED projects:
- Checklists: To ensure that all external tasks are completed and that all necessary items are available before the stoppage.
- Standardization of components: Use bolts, nuts, clamps, and other fasteners of the same size and type to reduce the number of tools needed.
- Modular or duplicate tooling: Have sub-assemblies or complete tooling sets prepared for a quick changeover.
- Precise positioning systems: Locating pins, fixed stops, guides, to eliminate the need for manual adjustments and measurements.
- SMED changeover carts: Carts specifically designed and equipped with all the tools, parts, and instructions needed for a particular changeover, organized according to the sequence of use.
- “One-Touch Setup” technology: Design mechanisms that allow tools to be fastened or released with a single action, without the need for multiple turns or adjustments.
- Elimination of post-changeover adjustments: Ensure that the first piece produced after the changeover is already of good quality, eliminating the need for stops for adjustments.
- Video analysis: Record changeover processes to identify time and motion waste that is not obvious at first glance.
- Teamwork and brainstorming: Involve the team of operators and technicians in identifying improvements, as they are the ones who know the process best.
- Preventive maintenance of tooling: Ensure that tools and dies are in optimal condition to avoid problems during changeover or startup.
The future of SMED: Integration with Industry 4.0
The SMED methodology, although decades old, remains incredibly relevant and can be enhanced with Industry 4.0 technologies. Jasrotia (2025) stated that Single Minute Exchange of Die (SMED) integrated with Industry 4.0 enables predictive equipment maintenance, reducing the risk of unexpected breakdowns, minimizing setup delays, and improving equipment efficiency, which leads to cost reductions associated with maintenance and repair.
Industry 4.0 technologies can be used in:
- Sensors and IoT: Monitor the condition of tooling and predict maintenance or change needs. Provide real-time data on the changeover process.
- Augmented Reality (AR): Guide operators through the changeover steps with visual instructions superimposed on their field of vision.
- Simulation and Digital Twins: Simulate and optimize changeover processes before implementing them in the real world.
- Predictive maintenance: Anticipate failures in tooling that could prolong changeover times.
- Intelligent Management Systems: Schedule changeovers more efficiently based on real-time production and demand data.
Conclusion: SMED as a pillar of operational excellence
Single Minute Exchange of Die (SMED) is much more than a simple technique for reducing time; it is a philosophy of continuous improvement that drives efficiency, flexibility, and competitiveness throughout the organization. By defining single minute exchange of dies and understanding its meaning, companies can unlock significant improvement potential.
Implementing SMED requires systematic effort, commitment, and the active participation of all levels of the organization. However, the benefits—from cost and inventory reductions to increased customer responsiveness and higher employee morale—make the investment worthwhile.
If your organization seeks to optimize its changeover processes, reduce waste, and thrive in a dynamic market, exploring and implementing SMED techniques is not just an option, but a strategic necessity. Start by analyzing your current processes, identify opportunities, and take the first step towards transforming your changeover times.
Frequently asked questions (FAQ) about Single Minute Exchange of Die (SMED)
What exactly does “Single Minute” mean in SMED?
“Single Minute” refers to achieving a changeover time in a single-digit number of minutes, i.e., less than 10 minutes. It does not necessarily imply that every changeover must be performed in 60 seconds, although that is the ideal towards which highly optimized applications tend.
Does SMED only apply to large manufacturing companies?
No. Although it originated in large industry, SMED principles are scalable and applicable to companies of all sizes and in various sectors, including services. Any process involving a preparation or changeover time can benefit from SMED.
What are the most common mistakes when implementing SMED?
Some common mistakes include:
- Not obtaining management commitment.
- Not involving operators in the improvement process.
- Focusing only on internal operations without addressing external ones.
- Not standardizing the new procedures.
- Considering SMED as a one-time project instead of a continuous improvement process.
- Underestimating the need for training.
How long does it take to see results with SMED?
Initial results, especially from separating internal and external tasks (Stage 1), can often be seen quickly, sometimes within weeks. Achieving more significant reductions (Stage 2 and 3) may take longer, depending on the complexity of the process and the resources invested.
Is it necessary to invest a lot of money to implement SMED?
Not always. Many SMED improvements are achieved through organizational changes, standardization, and the application of low-cost principles. While some solutions may require investment in tooling or modifications, the initial focus is usually on improvements that do not require large capital outlays.
How does SMED relate to other Lean methodologies like 5S or TPM?
SMED is a key tool within the Lean Manufacturing system. It complements other methodologies very well:
- 5S (Sort, Set in Order, Shine, Standardize, Sustain): Good workplace organization is fundamental for performing quick and efficient changeovers.
- TPM (Total Productive Maintenance): Ensuring that machines and tooling are in good condition reduces the probability of problems during changeovers and startup.
- JIT (Just-in-Time): SMED is an essential enabler of JIT, as it allows for efficiently producing small batches.
What is the difference between “single minute exchange of die” and “single minute exchange of dies”?
Both phrases refer to the same concept. “Die” is singular (a matrix or mold), while “dies” is the plural. In the context of SMED, it refers to the change of “the tooling” or “toolings,” so both forms are commonly accepted and understood. The essence of the single minute exchange of dies meaning is the same: the drastic reduction of changeover time.
References
Carrizo Moreira, A., & Campos Silva Pais, G. (2011). Single minute exchange of die: a case study implementation. Journal of technology management & innovation, 6(1), 129-146.
Che Ani, M. N. b., & Shafei, M. S. B. S. (2014). The Effectiveness of the Single Minute Exchange of Die (SMED) Technique for the Productivity Improvement. En AMM.465-466 (Artículo ID 1144). Trans Tech Publications. https://doi.org/10.4028/www.scientific.net/AMM.465-466.1144
Desai, M., & Rawani, A. M. (2017). Productivity improvement of shaping division of an automobile industry by using single minute exchange of die (SMED) methodology. ARPN Journal of Engineering and Applied Sciences, 12(8), 2615-2629.
Farwaha, H. S., Singh, P., Kumar, M., Ranjan, N., & Kaur, H. (2024, February). Enhancing sustainability in manufacturing: A case study on reducing changeover time through single minute exchange of dies and risk analysis. In AIP Conference Proceedings (Vol. 3050, No. 1). AIP Publishing.
Freitas, A. de O., Pimentel, C. A., Maia, V. K. F., & Araujo, A. C. B. de. (2025). Aplicação do Single Minute Exchange of Die (SMED) para redução do setup na enfermaria de um hospital obstétrico. Brazilian Journal of Production Engineering, 11(2), 94–106. https://doi.org/10.47456/bjpe.v11i2.47258
Godina, R., Pimentel, C., Silva, F., & Matias, J. C. (2018). A Structural Literature Review of the Single Minute Exchange of Die: The Latest Trends. Procedia Manufacturing, 17, 783-790. https://doi.org/10.1016/j.promfg.2018.10.129
Hasabe, A., Hakde, A., Khandagle, A., & Surve, K. (2019). Single minute exchange of dies (SMED) concept. International Research Journal of. Eng Technol, 6(04), 4665-4669.
Jasrotia, M. S. (2025). Digital SMED: Revolutionizing Setup Time Optimization using Industry 4.0. International Journal of Engineering Research & Technology, 14(01). https://doi.org/10.17577/IJERTV14IS010125
Junior, R.G.P., Inácio, R.H., da Silva, I.B. et al. A novel framework for single-minute exchange of die (SMED) assisted by lean tools. Int J Adv Manuf Technol 119, 6469–6487 (2022). https://doi.org/10.1007/s00170-021-08534-w
LOPES, João Paulo Pereira; BOVÉRIO, Maria Aparecida; SILVA, Dejaime Pereira da. METODOLOGIA SINGLE MINUTE EXCHANGE OF DIE (SMED): pesquisa de revisão bibliográfica. Ciência & Tecnologia, [S. l.], v. 16, n. 1, p. e16118, 2024. DOI: 10.52138/citec.v16i1.407.
Nájera, J. L., Saenz-Díez, J. C., Martínez-Cámara, E., Jiménez-Macías, E., Bruzzone, A., & Blanco-Fernández, J. (2024). Methodology to maximize zero losses through SMED in foodindustry. Dyna, 99(3).
Singla, V., & Mohan, T. (2024). Examining the Role of Single Minute Exchange of Die and Kanban in Productivity Improvement. IUP Journal of Operations Management, 23(1), 5–15.
Sundaramali, G., Kandavel, T. K., Raj, K. S., & Anirudh, S. (2024). Application of SMED to improve overall equipment effectiveness of die change over activities in a forging industry-a case study. International Journal of Productivity and Quality Management, 42(4), 445-458.
Editor and founder of “Innovar o Morir” (‘Innovate or Die’). Milthon holds a Master’s degree in Science and Innovation Management from the Polytechnic University of Valencia, with postgraduate diplomas in Business Innovation (UPV) and Market-Oriented Innovation Management (UPCH-Universitat Leipzig). He has practical experience in innovation management, having led the Fisheries Innovation Unit of the National Program for Innovation in Fisheries and Aquaculture (PNIPA) and worked as a consultant on open innovation diagnostics and technology watch. He firmly believes in the power of innovation and creativity as drivers of change and development.
