Quick Changeovers & SMED

Quick Changeovers & SMED 6

Learning Objectives At the completion of this unit the participant will be able to: • What are Quick Changeovers? • Why Quick Changeovers? • The 8 Steps to Quick Changeovers • What is SMED? • The 7 Steps to SMED © 2009 RLM & Associates LLC

What is a Changeover? The amount of time taken to change a piece of equipment from producing the last good piece of a production lot to the first good piece of the next production lot © 2009 RLM & Associates LLC

Why Quick Changeovers? • Reduce lot sizes • When lot sizes are reduced, the customer’s lead time is also reduced • This is because most of the lead time is waiting (queue time) © 2009 RLM & Associates LLC

8 Techniques to Quick Changeover • Separate internal from external setup operations • Convert internal to external setup • Standardize function, not shape • Use functional clamps or eliminate fasteners altogether • Use intermediate jigs • Adopt parallel operations • Eliminate adjustments • Mechanization © 2009 RLM & Associates LLC

Focus on the Process, not the Technology • SMED should be inexpensive • Well planned • Well practiced • Well executed • Without Standard Work, there is no continuous improvement © 2009 RLM & Associates LLC

Shingo’s Success Changing dies on stamping machines took up to three days to complete • Placed precision measuring devices on the die – used instead of eyeballing • Tools designated for SMED were located close by • Cut the changeover time to less than 10 minutes! © 2009 RLM & Associates LLC

7 Steps to Implementing SMED 2. Separate the INTERNAL and EXTERNALactivities. Internal activities are those that can only be performed when the process is stopped, while External activities can be done while the last batch is being produced, or once the next batch has started. For example, go and get the required tools for the job BEFORE the machine stops. © 2009 RLM & Associates LLC

7 Steps to Implementing SMED 4. Streamline the remaining Internal activities, by simplifying them. Focus on fixings - Shigeo Shingo rightly observed that it's only the last turn of a bolt that tightens it; the rest is just movement. © 2009 RLM & Associates LLC

Only the final turn on a bolt adds value • The interrupted screw (or interrupted thread) provides one means of clamping and unclamping something quickly. Artillery breeches have been sealed in this manner since the nineteenth century. © 2009 RLM & Associates LLC

7 Steps to Implementing SMED 7. Do it all again: For each iteration of the above process, a 45% improvement in set-up times should be expected, so it may take several iterations to cross the ten-minute line. © 2009 RLM & Associates LLC

Look For • Shortages, mistakes, inadequate placement of needed equipment. Can be avoided by using check tables, especially visual ones, and setup on an intermediary jig. • Inadequate or incomplete repairs to equipment. • Optimization for least work as opposed to least delay. © 2009 RLM & Associates LLC

Look For • Unheated molds which require several wasted 'tests' before they will be at the temperature to work. • Equipment using slow, precise adjustments for the large coarse part of adjustment. • Lack of visual lines or benchmarks for part placement on the equipment. © 2009 RLM & Associates LLC

Look For • Forcing a changeover between different raw materials when a continuous feed, or near equivalent, is possible. • Lack of functional standardization, that is standardization of only the parts necessary for setup, e.g. all bolts use same size spanner, die grip points are in the same place on all dies. © 2009 RLM & Associates LLC

Look For • Much operator movement around the equipment during setup. • More attachment points than actually required for the forces to be constrained. • Attachment points that take more than one turn to fasten. © 2009 RLM & Associates LLC

Quick Changeovers & SMED