Frequently Asked Questions
A changeover time reduction program should begin by classifying activities involved in the changeover. EXTERNAL activities are those that can be done whilst the previous batch is still running. With these, the maximum amount of preparation should be done before changeover (e.g. locate tools and dies ready for the changeover).
INTERNAL activities can only be done whilst operations are stopped. Internal activities should be checked to see if they can be made external activities (e.g. pre-heating a die). The sequence of internal activities should be reviewed and those that can be done simultaneously should be, using a team of people if necessary. Improved jig, tool and fastener design can also help reduce changeover times. The aim is to get the first perfect piece, from the next batch, as fast as possible.
Other considerations for reducing changeover times are:
- video changeovers, view them and brainstorm improvements
- use cause and effect diagrams to organise and prioritise ideas
- sequence batches to minimise changeover activities
- monitor changeover times and seek continual reductions
- use people who normally work on non-bottleneck processes to assist with changeovers on bottleneck processes
- consider whether a dedicated machine is appropriate to eliminate changeovers entirely
For more information, please contact us.
References:
Bicheno, J., Cause and Effect JIT: The Essentials of Lean Manufacturing, 2nd Edition, PICSIE Books, Buckingham, England, 1994 (ISBN 0 9513829 5 0)