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.
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.
In today’s manufacturing arena equipment reliability is paramount, thus we are seeing more and more companies trying to implement Total Productivity Manufacturing (TPM). TPM is not a program that can be implemented over night and takes commitment at all levels of the organization to be successful. One major indicator of a successful TPM program is Overall Equipment Effectiveness (OEE). This OEE number can be challenging to obtain for most companies and involves six major areas of equipment losses: Setups and Adjustments, Breakdowns, Idling and Minor Stoppages, Start-ups, running at Reduce Speed, Defects and Rework.
When setting out on the journey to become a Lean organization, companies often miss the true importance of utilizing Value Stream Mapping. Often companies overlook implementing Step Four (Value Stream Mapping product families), as outlined in Chapter 11 of Lean Thinking. This can be a critical mistake in creating a sustainable Lean Initiative.
Value Stream Mapping should be viewed as the backbone of any Lean Initiative and process improvement endeavors. Simply picking trouble areas for improvement without examining the entire value stream of the product family or families utilizing the resource can create undesirable results long term. Value Stream Mapping provides us with the information necessary to understand the actual flow of materials, resources and information through all processes from start to finish for the family of products or services chosen. By obtaining this knowledge, we can see where flow is interrupted and where to start making improvements that increase the flow across the value stream. Simply attacking a troubled area in the process without understanding the true value stream could introduce additional WIP (work in process) and inefficiencies in the processes, thus increasing the process lead time across the overall value stream.
Value Stream Mapping provides us with a tool to start process improvement through a systematic approach. We start by mapping the current state for a particular product family from start to finish usually within the four walls of a facility. From this current state map, we apply Lean tools to create a future state map with an improve process lead time focused on eliminating waste and creating flow across the entire value stream. This future state map dictates where and what type of Kaizen Events (Improvement Events) will be required to meet the future state map objectives. The results of our future state map implementation are evaluated against the performance metric objectives developed for the future state value stream. The future state accomplished through our deployment of Kaizen Events is now our current state for the value stream. A period of evaluation should be performed and the value stream mapping process repeated to create a new future state map. This process could take place several times in the journey to become a World Class Company. Typically value stream mapping plans should be developed with implementation to be completed within (6 -12) months. This process is repeated for all value streams across the organization to achieve world class improvement results. The true value in value stream mapping is the creation of process improvement plans that can be implemented systematically across the company with sustainable results.