Preventive Maintenance: hard schedule versus last performance based.
When scheduling monthly preventive maintenance (PM), the intention is simple – to repeat the set of activity every 30 days. When it comes to the implementation, things became less clear:
Monthly bearing lubrication. PMs were done at Jan-31, Feb-1, and Mar-31. Does it comply with the formal schedule? Sure! But is it answering to the monthly preventive maintenance idea? Of cause not! The tool has not treated for 60 days instead 30 and Feb-1 PM was useless.
Same PM. PMs were done at Jan-31, Mar-5, and April-4. Obviously, February PM was not done but the lubrication frequency is better – 30 to 33 days. Based on the actual tool’s condition, maintenance team may even increase the number of days between PMs!
Monthly calibration (measurement equipment, subject for the external audit). Here is no choice – accurate listing of monthly PM is a must.
Both tools should be maintained in the same system, with the same rules. When comparing between Case 1 and Case 2, PM based on the last performance is better, but for the Case 3 it is not an option... Is an efficiency being more important than a bureaucracy, or system approach worth few hours of excessive downtime? We will appreciate your answers! To be continued...