Is time on your side?

Too often, companies are quick to implement new equipment in order to meet increased customer demand for products, without maximizing the utilization of their current equipment.  Equipment changeover time is one area of the business that is often ignored and companies accept long changeover as a part of doing business.  The changeover time of equipment can be a Hidden Factory just waiting to be uncovered.  It is very common for equipment changeover from one product to the next product, to take a couple hours for completion.  Companies often make several product changeovers per week, consuming hours of potential production time.  If we could somehow reduce the changeover time from hours to minutes, we could have a dramatic effect on providing additional production capacity.  This is what Dr. Shigeo Shingo discovered while helping to develop the Toyota Production System.  Dr. Shingo terms his discovery SMED (Single Minute Exchange of Dies), and it prescribe that changeover time should be less than ten minutes for a given product.

What does SMED Involve?

Companies can systematically reduce changeover time on their equipment by following a simply four step method.

1. Document the current changeover process and break the process into elemental steps.  This is typically done through the shooting of a changeover video of the process and reviewing the video to document the steps and times associated with each step.  The steps are also classified as internal (Step occurs while the equipment is not running) or external (Step occurs while the equipment is running and producing product).
2. Review each process step: Is it necessary or can it be eliminated.  During the review, ideas are generated on how to convert internal steps to external steps.  Internal steps in the changeover process are the driving factor for the overall changeover time on the equipment.   Thus, reducing the internal steps has a dramatic effect on the overall changeover time for the equipment.
3. Re-examine the remaining internal steps with the goal of (Streamlining, Combining or Eliminating) the steps.   Often steps can be performed in parallel with the addition of Assist Operator during the equipment changeover.  Working as a team and performing parallel operations can have a dramatic effect on reducing the time on the equipment changeover.
4. Focus on eliminating adjustments for the remaining internal setup steps.  In this step, the reliance on “Tribal Knowledge” is significantly reduced or eliminated through the development of hard settings for the equipment.  Often the equipment is updated with scales, gauges, and visual controls that can be used to establish initial settings for running a particular product on the equipment.  By establishing initial settings based on past production runs, the trial and error time at start-up can be significantly reduce and the equipment can produce good product much faster.

SMED Four Step Process
Finally, after completing the SMED four-step process a new changeover standard can be developed using the remaining internal and external steps.   The new changeover standard should prescribe the changeover sequence and operators required to complete the changeover on the equipment.

For most companies that have not participated in any formal changeover reduction process on their equipment, applying the SMED approach typically reduces the changeover time by 50% when first applied.  By continuing to work as a team, planning changeovers, practicing, being innovative and standardizing changeover methods equipment changeover times can continue to be reduced.   Companies should strive to achieve the goal of single-minute changeover times and recapture the loss capacity due to long changeover times.

• Planning
• Practice
• Innovation
• Standardization
• Continuous Improvement