OEE Calculation
5S Training helps improve your quality and performance
OEE Calculation
The OEE calculation is essentially a plant KPI expressed as a Percentage. The three components are multiplied together as CAPPED percentages to provide the final result.
The calculation will target three main production losses:
Availability
This shows the relationship between planned production time less any unplanned stoppage. These stoppages will be major breakdowns that can be readily identified.
Performance
This shows the relationship between the units that should have been produced and those actual produced. The losses are usually due to speed losses (Machines running to slowly) and minor stoppages. (events that happen quickly and can not be easily captured)
Quality
This shows the relationship between good pieces produced and rejected parts. It is effectively a "first time right figure". Six Sigma Methodology can be used with OEE to reduce waste
The Components of the OEE Calculation
Availability
Availability is the parameter that takes into account downtime. When a machine is not running due to a fault you are losing planned production time :
Availability = Operating Time / Planned Production Time
Performance
Performance = (Ideal Cycle Time * Pieces Produced) / Operating Time
Ideal Cycle Time is the maximum speed the machine can run expressed as a unit cycle time. It is sometimes called Name Plate Cycle Time.
Performance is capped at 100%, This will ensure if a cycle time is specified too low the performance figure will not distort the calculation.
Quality
Quality takes into account wastage due to poor Quality.
Quality = Good Pieces / Pieces Produced
The worldwide average for Overall Equipment Efficiency / Effectiveness in manufacturing plants is between 45 and 60 percent. To achieve 'world class' manufacturing status a level of 85% or better should be targeted.
Every plant and manufacturing process is different. If you operate a policy of Six-Sigma then quality levels of 96.5 % would be unacceptable - 99.99% would be a better target to achieve. The OEE calculation provides a tool for progressive improvement.