Step 5 is focused on reducing process downtime. The two main causes of process downtime are 1) equipment changeovers and 2) equipment failures or breakdowns. The time that a piece of equipment is being changed from running one product to running the next product or fails to run it is unavailable for the process. This results in lost processing time which cannot be recovered. The best methods to reduce these main causes of process downtime is to implement Quick Changeovers (SMED) and Maintenance Excellence (MEX) systems.
What is a Quick Changeover?
A Quick Changeover is an improvement process using the SMED concept for reducing equipment downtime. The definition of a changeover is the time between the last good part of the current run until the first good part off the next run. The time taken to set up a process is non-productive and therefore, non value added from a customer’s perspective. It takes longer to manufacture components because orders have to wait until the equipment can produce a good part before an order can be started and the work completed. Lead time increases because of long changeover times.
What are the steps in a Quick Changeover?
There are four steps to implementing SMED:
1. Document and record a changeover to identify the activities
2. Separate activities into internal and external elements
3. Convert internal into external elements
4. Streamline all aspects of the changeover process
What effect will SMED have on production?
Long changeover times force a business to manufacture large batches of products to compensate for the downtime. Implementing quick changeovers using SMED will reduce the amount of time to set up a machine. This in turn will reduce lead time and increase production hours.
What is Maintenance Excellence (MEX)?
Maintenance Excellence is part of the Total Productive Maintenance (TPM) system. It includes elements from the Autonomous Maintenance procedures which requires operators to participate in regular point inspections by following a standard checklist. Analysis demonstrates that 85% of all breakdowns can be avoided if operators are training to recognize potential issues early and inform the maintenance dept.
Reduce Process Downtime Video
In this short video, Chris Turner – Lean Mfg. Coach gives a brief explanation about the Quick Changeover process.