Equipment Management Metrics
Many companies are realizing that large investment in improving equipment reliability does not necessarily translate in to overall increase in reliability. Reliability investment must be focused on prioritized improvements and which have a direct impact on system reliability.
Equipment management metrics are used to assess reliability and maintainability and indentify problems.
Mean time Between Failure ( MTBF) , Mean time to Failure (MTTF) and Mean time to repair (MTTR) are some of the performance indicators used to measure reliability and maintainability of a piece of equipment
MTBF/MTTR are digramatically represented in the picture below digram.
Criteria’s for Reliability and Maintainability measurement
1. MTBR is MTBF minus MTTR. Therefore the longer the MTBR, the more reliable the equipment is.
2. MTTR is the maintainability of the equipment, How fast the equipment can be restored
3. More frequent MTTR however small it is , indicates improper maintenance procedure/ or fundamental issues with the equipment like alignment etc
4. Each MTTR plotted against formalized defect and Cause codes gives repetitive problems on the machine.
5. The availability of equipment then becomes MTBF/MTBF + MTTR.
6. Reliability can be expressed as MTBF/1+MTBF and Maintainability as 1/1+MTTR
SAP provides online standard report on MTBF and MTTR. Using custom development it is possible to determine Reliability and Maintainability of a piece of equipment.
The above content is only author’s opinion based on his experience.
Comments
please provide transactions throuhg i can find out above MTTF, MTTR and MTBR
Posted by: SYED YOUSUF | December 17, 2009 11:56 AM