In lean manufacturing, reducing changeover times is a crucial aspect of improving efficiency. SMED (Single-Minute Exchange of Die) or quick changeover techniques provide a systematic approach to minimize changeover times, leading to increased productivity and reduced downtime. This article presents the proper order for applying SMED techniques, drawing from reputable sources such as PTC, Lean Production, and AllAboutLean.
Key Facts
- Step One – Identify Pilot Area: Select a target area or equipment for the pilot SMED program. Choose equipment that has a significant room for improvement in changeover time but is not overwhelming in scope. Consider factors such as duration, variation, opportunities for changeover, familiarity, and constraint/bottleneck status.
- Step Two – Identify Elements: Work together with a team to identify all the elements involved in the changeover process. This can be done by videotaping the entire changeover and creating an ordered list of elements based on the video. Each element should have a description and time cost.
- Step Three – Separate External Elements: Identify elements of the changeover process that can be performed while the equipment is running or with minimal change. Move these elements “external” to the changeover, meaning they are performed before or after the changeover. This step can significantly reduce changeover times.
- Step Four – Convert Internal Elements to External: Examine the current changeover process and identify internal elements that can be converted to external elements. Prioritize these elements based on their potential for improvement. Perform a cost/benefit analysis for each candidate element and make the necessary changes to convert them to external elements.
By following these steps, companies can effectively implement SMED or quick changeover techniques to reduce changeover times and improve efficiency in their operations.
Step-by-Step Application of SMED Techniques
Step One – Identify Pilot Area
The initial step involves selecting a target area or equipment for the pilot SMED program. This selection should consider several factors:
- Duration: The changeover time should be long enough to offer significant room for improvement, but not excessively long to avoid overwhelming the scope.
- Variation: Look for equipment with substantial variation in changeover times, indicating potential for improvement.
- Opportunities: Frequent opportunities for changeover allow for quicker testing of proposed improvements.
- Familiarity: Engage employees familiar with the equipment, including operators, maintenance personnel, quality assurance, and supervisors, to ensure their involvement and motivation.
- Constraint/Bottleneck Status: Prioritize equipment that is a constraint or bottleneck, as improvements will yield immediate benefits.
Step Two – Identify Elements
In this step, a team works together to identify all elements involved in the changeover process. This can be achieved by:
- Videotaping: Record the entire changeover process on video to create an accurate and comprehensive list of elements.
- Ordered List: Based on the video, create an ordered list of elements, each with a description and time cost.
Step Three – Separate External Elements
The next step is to identify elements that can be performed while the equipment is running or with minimal change. These elements are moved “external” to the changeover, meaning they are performed before or after the changeover. This step often leads to significant reductions in changeover times.
Step Four – Convert Internal Elements to External
The focus now shifts to examining the current changeover process and identifying internal elements that can be converted to external elements. This involves:
- Prioritization: Prioritize internal elements based on their potential for improvement.
- Cost/Benefit Analysis: Perform a cost/benefit analysis for each candidate element, considering the materials and labor required for changes versus the time saved in the changeover.
- Necessary Changes: Make the necessary changes to convert internal elements to external elements, such as advance preparation, use of jigs, modularization, equipment modification, and more.
Conclusion
By following these steps, companies can effectively implement SMED or quick changeover techniques to reduce changeover times and improve efficiency in their operations. This systematic approach enables the identification and conversion of internal elements to external, resulting in faster changeovers and increased productivity.
References
- PTC: What is SMED? [https://www.ptc.com/en/blogs/iiot/what-is-smed]
- Lean Production: SMED (Single-Minute Exchange of Die) [https://www.leanproduction.com/smed/]
- AllAboutLean: Quick Changeover Basics – SMED [https://www.allaboutlean.com/smed-theory/]
FAQs
What is the first step in applying SMED techniques?
The first step is to identify a pilot area or equipment for the SMED program. This equipment should have significant room for improvement in changeover time but not be overwhelming in scope. Factors to consider include duration, variation, opportunities for changeover, familiarity, and constraint/bottleneck status.
How do you identify elements in the changeover process?
To identify elements in the changeover process, videotape the entire changeover and create an ordered list of elements based on the video. Each element should have a description and time cost.
What is the purpose of separating external elements in SMED?
Separating external elements in SMED involves identifying elements that can be performed while the equipment is running or with minimal change. These elements are moved “external” to the changeover, meaning they are performed before or after the changeover, which can significantly reduce changeover times.
How do you convert internal elements to external elements in SMED?
To convert internal elements to external elements in SMED, examine the current changeover process and identify internal elements that can be converted. Prioritize these elements based on their potential for improvement and perform a cost/benefit analysis for each candidate element. Make the necessary changes to convert them to external elements, such as advance preparation, use of jigs, modularization, equipment modification, and more.
What are some examples of external elements in SMED?
Examples of external elements in SMED include retrieval of parts, tools, materials, and instructions; inspection of parts, tools, and materials; cleaning tasks that can be performed while the process is running; and quality checks for the last production run.
What are some examples of internal elements in SMED?
Examples of internal elements in SMED include adjustments, alignments, and other tasks that require the equipment to be stopped; tool changes; and die changes.
What are some techniques used to convert internal elements to external elements in SMED?
Techniques used to convert internal elements to external elements in SMED include advance preparation, use of jigs, modularization, equipment modification, and more.
What are the benefits of implementing SMED techniques?
Implementing SMED techniques can lead to reduced changeover times, improved responsiveness to customer demand, lower inventory levels, smoother startups, and lower manufacturing costs.