Privacy policy and cookies

This site uses cookies. By continuing to browse the site you are agreeing to our use of cookies. Read our Privacy Policy
Overall Equipment Effectiveness (OEE)

Overall Equipment Effectiveness (OEE) is a performance measure commonly used to monitor successful improvements to a process/area/machine. OEE is designed to indicate how effectively a manufacturing operation is utilised.  OEE can at times be a complicated metric to understand as it is derived from three individual calculated components. The components of OEE are : Availability, Performance, and Quality.

 

To calculate an OEE for a single machine first you need to know your Availability, Performance and Quality.

  OEE= (AxPxQ)

• A =  Represents the percentage of scheduled time that the operation is available to operate. Often referred to as Uptime.

• P=  The speed at which the machine  runs as a percentage of its designed speed.

• Q= : The Good Units produced as a percentage of the Total Units Started.

 

How to calculated the components Availability, Performance, and Quality.

Availability is a measurement of Uptime.

Calculation: A = Available Time / Scheduled Time

Performance –  is a measurement of speed

Calculation: P= (Parts Produced * Ideal Cycle Time) / Available Time

Quality – measures the Good Units produced as a percentage of the Total Units Started.

Calculation: Q = Good Units / Units Started

Here is a working example on how to calculate Overall Equipment Effectiveness (OEE) for a single machine example. First you need to know your production data in order to calculate the inputs for 1) Availability, 2) Performance and 3) Quality elements. These include:

  • Hours per shift
  • Total break
  • Machine downtime
  • Planned run rate
  • Total units manufactured
  • Reject or rework pieces

1) Machine Availability

The Availability is the measurement of the time the machine was able to performance its function.

Calculation: Availability = Available Time / Scheduled Time

Example:

The CNC Lathe is scheduled to run for an 8 hour shift.

The normal shift includes total  of 45 minute meal breaks.

During the shift the Machine experiences 60 minutes of unscheduled downtime.

Scheduled Time = 8hrs – 0.75hrs break = 7.25hrs

Available Time = 7.25hrs Scheduled – 1 hours  Unscheduled Downtime =  6.25 hrs

Machine Availability = 6.25hrs/ 7.25 Scheduled = 86%

2) Performance

The Performance Metric is a measurement of speed that machine needs to run in order to performance its function.

Calculation: Performance = (Total units Manufactured * PLanned Run Rate) / Available Time

Example:

Available Time = 6.25 hrs

The Planned Rate for the part being produced is 40 Units/Hour or 250 part per shift

The Machine produced 242 Total Units during the shift.

Time to Produce Parts = 242 Units for the shift

Performance = 242 / 250 parts = 97%

3) Quality

The Quality metric measures the Good Units produced as a percentage of the Total Units produced.

Calculation: Quality = Good Units / Total Units produced

Example:

242 Units were manufactured in order to produce the 230 Good Units.

Quality = 230 Good Units / 242 total units manufactured = 95.0%

These percentages can now be entered into the standard formula for OEE.

OEE= (AxPxQ)

OEE= (86% x 97% x 95%)

OEE= 79%

This calculation can be performed easily with spreadsheet template for daily measure to be added to a team’s production board.