Waiting is identified as one of the 8 Wastes of Lean Manufacturing. It is wasted time waiting for the next step in the process. In many manufacturing organizations, Changeover is commonly identified as one of the highest contributing factors adding to waiting time.
A Changeover is defined as the amount of time it takes to go from the last good part of one product run to the first good part of the next product run.
Single Minute Exchange of Die (SMED) is a Lean tool used to decrease waiting time. It was developed by Shigeo Shingo in Japan in the sixties and early seventies at Toyota and other Japanese firms, in order to reduce costly inventories and improve efficiency.
An important foundation to the SMED system is the distinction between changeover work that occurs while the machine is not running, called Internal Setup, and preparatory work that occurs while the machine is running, called External Setup. At the point in time when SMED was developed, almost all changeover work was performed while the machine (press) was down.
SMED Methodology now seeks to re-organize and simplify operations, by performing as many operations as possible without the production being stopped. Effectively, it allows you to maximize lean flow and reduce setup time by moving tasks from ‘internal setup time’ (happening during the normal changeover process) to ‘external setup time’ (happening before or after the changeover process).
As Shigeo Shingo acknowledges: “The most dangerous kind of waste is the waste we do not recognize.”
To effectively analyze and improve the changeover process using SMED methodology, it is vitally important to base decisions on reliable data from a consistent measurement system.
Overall Equipment Effectiveness (OEE) has become the foundation of any Lean company. When used correctly, it provides teams with critical information about downtime activities on their machines, in this case downtime due to changeover activities. This information can then be used to inform and empower leaders to continuously improve in real-time every day, every hour, every minute! OEE will highlight a factory’s hidden capacity, identify waste and visualize losses for Waiting. OEE finds the REAL reasons behind losses and drives corrective action at the root cause, rather than the symptoms.
Manufacturers who have combined their SMED projects with OEE have seen huge improvements in changeover and setup reduction. Haldan Consulting’s clients (such as CRH Africa, Ebor Automotive Systems and Foxtec-Ikhwezi) were able to visualize the increase in changeovers and what this meant for their businesses, using our HaldanMES OEE software.
Check out the case studies to find out more about which actions returned the greatest results for their teams:
Quality and efficiency are crucial factors that contribute towards competitiveness and profitability in the manufacturing industry. This is the reason why lean manufacturing is perhaps the most important management approach for companies wanting to eliminate non-value adding steps in every process. Manufacturers are not only under pressure due to the increased demand for product capacity and flexibility, but also due to the need to operate with minimal inventory levels.
This means that projects like SMED and measurement systems like OEE are compulsory to maintain a competitive advantage.
