SMED as a method for optimizing production processes

Single-Minute Exchange of Die (SMED) is one of the most groundbreaking methods in lean manufacturing. Its goal is to significantly reduce machine changeover times. Therefore, it’s a valuable tool in highly competitive industries where rapid response to order changes can provide a competitive advantage. What does SMED offer? It not only increases efficiency and reduces downtime, but also reduces inventory levels, improves quality, and optimizes resource utilization. A CMMS can support this process – here’s what you need to know.

SMED – What is it? Introduction to the SMED method

SMED is a method developed by Japanese professor Shigeo Shingo in the 1960s and 1970s. It is part of the broader concept of lean manufacturing (lean production). Toyota pioneered this approach; today, it forms the basis of management for many industrial companies in various sectors. Individual components of lean manufacturing focus primarily on eliminating inefficient process elements. SMED focuses on minimizing the time required for tool or mold changes in production machines.

A classic changeover process consists of internal and external steps. The former require a machine changeover. The latter can be performed while the machine is running. The goal of SMED is to shift as many external steps as possible outside of downtime. Furthermore, tasks that must be performed while the machine is running are optimized. What is the result? When implemented correctly, changeover times are measured in minutes. Hence the name of this method – SMED stands for “Single-Minute Die Exchange.” This time can be achieved even for complex processes.

The origins and philosophy of SMED

SMED is based on the philosophy of continuous improvement (Kaizen). Shingo observed Toyota’s practices over the years and identified various problems with changeovers. These processes were often poorly planned, disorganized, and fraught with unnecessary activities. A simple solution to these problems is to shorten changeover times. But that’s not all. SMED follows a systematic approach—standardization, waste elimination, and continuous optimization.

The core idea of SMED is that tool changes don’t have to be annoying interruptions. Instead, they can become an efficient, even automated step in the production cycle. With SMED, this process no longer represents a production bottleneck. Instead, machines can be quickly and efficiently prepared for subsequent production runs.

Basic principles of SMED

SMED implementation is based on four basic principles:

1. Separation of internal and external activities. The starting point is an overview of all conversion steps. Subsequently, those that can be performed on a running machine are identified.
2. Converting internal activities into external ones. Where possible, the sequence and organization of work are changed. The goal is to complete as many tasks as possible outside of downtime.
3. Standardize processes. Develop clear instructions, procedures, and checklists. This will prevent uncertainty and operator errors.
4. Continuous improvement. What are we talking about? This includes the regular analysis and improvement of changeover processes, the elimination of unnecessary movements, and the shortening of workflows. This also includes the implementation of innovative tools and technical solutions.

These four elements form the foundation for SMED success. However, it’s important to note that this is only the beginning of a full implementation of this method. The subsequent steps of SMED application are also crucial. These primarily involve careful observation and measurement, followed by optimization of individual steps.

Phases of SMED implementation

We now know what SMED is based on. But what does the practical implementation of this method look like? Implementation typically involves several steps. The first step is data collection and observation. The current changeover process must be recorded, the time for all steps measured, and the materials, tools, and people involved documented. The activities can then be analyzed and classified. This is done by dividing them into internal and external activities. Potential opportunities for rescheduling tasks outside of downtime can be identified.

Another important element of SMED implementation is the optimization of external processes. What does this mean? It primarily involves preparing all necessary tools, molds, and parts. It is important that they are available before machine downtime. This also involves material safety. SMED also involves the conversion of internal processes. This includes changing the work sequence, implementing a modular tool layout, and using automated systems or special changeover systems.

What else does SMED include? In addition to physical implementation, documentation is also important. Standardized procedures contribute significantly to efficiency. Step-by-step instructions, checklists, and visual plans are helpful. Furthermore, it is important to raise employee awareness. Operator training, audits, and regular inspections contribute significantly to the success of SMED.

Advantages of shortening changeover times

The primary goal of SMED is to accelerate changeover processes. This, in turn, offers numerous benefits to the entire plant. What are we talking about? For example, greater production flexibility. Shorter changeover times lead to more frequent product changeovers. This is a significant advantage, especially in small-batch production. Furthermore, SMED reduces work-in-progress (WIP) inventory. Thanks to faster tool changeovers, fewer semi-finished products remain on the lines, reducing inventory costs.

But that’s not all. SMED also means higher machine availability. Less downtime and faster line recovery – these aspects simultaneously lead to higher production. This benefit also goes hand in hand with reduced operating costs. Operators and technicians spend less time on changeovers. Wear and tear on consumables is also reduced. Taken together, this leads to real cost savings.

It’s also worth noting that SMED does not negatively impact quality. Quite the opposite. Standardization and the avoidance of haste reduce the risk of product defects. Furthermore, SMED can reveal further potential for improvement. Examples include improved workplace organization and the optimization of internal logistics. Proper SMED implementation allows for its combination with other improvements, thus increasing the overall efficiency of the entire plant.

CMMS and SMED

What is the relationship between CMMS systems and SMED? There’s no direct connection—SMED is a methodology that focuses on the transition process, while CMMS focuses on optimizing maintenance processes. However, these areas can be combined to facilitate SMED implementation. How can this be achieved? One good idea, for example, is to store procedures in the CMMS—the system can serve as the basis for SMED instructions. This way, operators always have access to the most up-to-date procedures.

In addition, a CMMS can record changeover times. This works according to the same principle as for repairs. Recording start and end times in the system allows progress to be monitored and potential deviations to be identified. At the same time, a CMMS enables maintenance work to be scheduled so that it does not disrupt production—this functionality can also be used for changeover operations. Another advantage of a CMMS is reporting and easy data analysis. The system collects information on failures, downtime, and labor efficiency. This, in turn, provides valuable insights for further optimization of changeover operations.

SMED – Challenges and best practices

Implementing SMED can be challenging. Three main problems can be identified: familiarity with procedures, lack of standardization, and technical limitations. How can these challenges be overcome? Operator involvement is particularly important, as they are most familiar with the process details. Furthermore, it is advisable to ensure order, cleanliness, and station labeling (5S approach). Quick-connect tools are helpful in implementing SMED – although they are more expensive, the investment in such solutions pays off through reduced downtime. Monitoring and reporting are also crucial: only the continuous tracking of key performance indicators ensures the sustainability of the improvements achieved.

SMED is an effective, proven method that reduces changeover times to a single minute. Its foundations are standardization and waste elimination. Achieving full results requires the commitment of the entire team. However, a CMMS can significantly simplify the implementation process by supporting the storage of procedures, task time tracking, and maintenance planning. This allows organizations to gain flexibility, greater machine availability, and improved quality. If you’re considering optimizing your changeover processes, consider working with QRmaint – our specialists are ready to hear from you.