Steps to Reduce Changeover Time and Unlock Free Capacity

Unlocking Efficiency with SMED in Lean Manufacturing

Single Minute Exchange of Dies (SMED) is a pivotal process in lean manufacturing that focuses on reducing changeover or setup time. By identifying and eliminating unnecessary steps in the changeover process, SMED minimizes costly downtime associated with equipment replacement. This method enhances productivity, lowers waste, and reduces costs.

The Basics of SMED

SMED is a core principle of lean manufacturing aimed at reducing equipment changeover times to under 10 minutes. This process encourages performing as many preparatory steps as possible before the changeover, having teams work in parallel, and creating standardized, optimized procedures. Developed by Japanese industrial engineer Shigeo Shingo, SMED has proven to reduce changeover times significantly, sometimes by up to 94%.

Benefits of SMED

1. Smaller Lot Sizes: Efficient changeovers enable seamless product transitions, reducing inventory costs, waste, and space requirements.
2. Lower Manufacturing Costs: Reduced changeover time minimizes material costs and scrap by up to 50%.
3. Standardized Procedures: Quicker changeovers decrease equipment downtime and optimize processes by performing many steps while machines are still running.
4. Increased Machine Work Rates: Streamlined changeover processes allow machines to continue running, facilitating faster start-up times.
5. Better Responsiveness to Customer Demand: Smaller lot sizes and streamlined workflows enhance production planning and alignment with customer needs.

Considerations for SMED Implementation

Before implementing SMED, evaluate the least efficient aspects of your current processes. Using Industrial Internet of Things (IIoT) technology can provide real-time visibility into plant operations, identifying areas not operating at maximum efficiency. Consider the following before selecting a target area:

• High duration and variation in changeover time
• Regular changeover occurrences for performance measurement
• Employee familiarity with equipment
• Equipment as a bottleneck for other processes

External vs Internal

Within SMED, a changeover is split into two distinct parts: an external setup and an internal setup.

External Setup: External setup tasks are activities that can be done while the current production process is still running. For example, collecting necessary tools or pre-treating. Doing these activities does not disrupt the current production process.

Internal Setup: Internal setup tasks are activities that can only be performed when the machine or process has stopped. An example of this would be the insertion of a new fill head. This activity is not possible to do on an active machine or production line.

The objective of SMED is to transition as many internal setup steps to external steps as possible. This would result in a reduction in process downtime for changeovers.

It is most well-known in automotive plants and complex machine shops, where a changeover can take hours to days to switch from producing one model to another. However its also highly beneficial in other high-mix, lower-volume production factories like specialty chemical batch manufacturing or even food production, where changeovers for different customers of different product types can be multiple times in a day, for example even a 5-minute changeover can result in 100 minutes of downtime in a day which is significant, and being able to reduce that down to a 2.5-minute changeover would save 50 minutes or around 10% of a standard shift time.

Steps for SMED Implementation

1. Identify Pilot Area: Ensure employees are confident and motivated to provide step-by-step instructions, enhancing understanding and reducing errors.
2. Identify Internal and External Components: Understand the processes that need the equipment stopped (internal) and those that can be done while running (external). Ensure tools and supplies are ready for changeovers.
3. Convert Internal to External Components: Analyze each component to determine if it can be managed while the machine is running. Utilize IIoT to convert internal components, reducing overall changeover time.
4. Streamline Internal Elements: Optimize the remaining internal components using IIoT solutions to increase productivity and reduce inefficiencies.

Start simple, then look to go digital

Implementing SMED is a significant step towards faster start-up times and streamlined material workflows. You can start simple with manual data collection, then progress to smart, connected manufacturing lines that can provide data to drive improved operations and efficiencies, facilitating routine maintenance, Overall Equipment Effectiveness (OEE) and continuous improvement. Embracing SMED as part of manufacturing solutions enhances operational efficiency, paving the way for sustained productivity and growth.