The majority of mangers do not fully understand the impact equipment reliability has on their bottom line.  If you are trying to:

Increase Equipment Reliability

Increase First-Time-Through Quality

Increase Mean-Time-Between-Failures

Increase Production Manpower Efficiency

Increase Maintenance Manpower Efficiency

Gain Full Control Of Your Equipment

Lower Mean-Time-To Repair

Lower Maintenance Costs

Lower Inventory Costs

Lower Energy Costs

Then you need to focus on Equipment Reliability! 

To be able to improve equipment reliability you first must understand how you are doing? To measure Equipment Reliability you would use the following measurements: Over-All Equipment Effectiveness (OEE), Mean-Time-To-Repair (MTTR) and Mean-Time-Between-Failures (MTBF).  These 3 measurements are higher-level measurements or Flag measurements that will give you the bigger picture of what is happening with regards to equipment reliability. These 3 measurements can also be used to help find your bottleneck equipment / system / component / process which are causing you unforeseen outages. There are other measurements that can be used to accent these measurements; we will talk about these later.

Over-All Equipment Effectiveness (OEE) is a measurement that came from Total Productive Manufacturing.  OEE is made up of 3 individual measurements; these are: Availability (%), Process Rate (%), and Quality Rate (%). These 3 measurements are then multiplied together to give you the OEE measurement. OEE is a percentage measurement and is not a hierarchical measurement. You must take separate OEE measurement readings on each piece of equipment and one for the line or cell.  OEE measurement allows you to understand the production side of the equation.  Note: You cannot have more then 100% OEE.  If you have over 100% OEE - you calculation is faulty. 

Mean-Time-To-Repair (MTTR) is a Maintainability measurement.  This measurement is used to understand on average how long it takes to repair when an outage occurs.

Mean-Time-Between-Failures (MTBF) is a Reliability measurement.  This measurement is used to understand on average how long the equipment runs before an outage occurs.

I have always found it amazing how managers try to manipulate measurements to make them-selves look better. The only way you can improve is to be honest and gain an accurate knowledge of the problem.  No "Rose" colored glasses! If you are a senior manager and you have to add a "fudge" factor or, do not trust the measurements; then you need to deal with the people problem!

Once  you have performed an analysis of your lines / equipment. You can see were you need to improve.  A longer-term target for OEE is 85%.  Most North American manufactures operate at less 60%OEE.  For MTTR and MTBF the ideal goal should be "ZERO" unplanned outages.  Thus, ideally MTTR would be "zero" and MTBF would be exponential.

Note: The information contained in this blog is the opinion of the author and is intended for discussion purposes only.