Measuring Production with OEE

OEE = Availability x Performance x Quality

Whether a company is considering 5-S, Total Production Maintenance (TPM) or Learn manufacturing, OEE (Overall Equipment Effectiveness) should be added to the list of production improvement initiatives. OEE is a way for companies to quickly identify issues with machine productivity, manufacturing cells or assembly lines. This powerful key performance indicator consists of three primary components: Availability, Performance and Quality.

Availability – availability takes into account unplanned down time. This includes equipment failures, material shortages, and changeover time. Consider the following example:

– Shift = 480 minutes (8 hours)
– Breaks = 40 minutes
– Meals = 30 minutes
– Down time = 35 minutes (due to operational issues)

This results in an availability score of 91%.

 Performance – performance measures speed, which includes factors that cause the process to operate at less than the maximum run rate. This includes machine wear, substandard materials, and operator inefficiency. For example:

– Total pieces complete = 15,000 pieces
– Total scheduled uptime = 375 minutes
– Ideal run rate per minute = 45 pieces per minute

This results in a performance score of 88%.

Quality – quality accounts for production losses, which factors out manufactured pieces that do not meet company standards including rework pieces. For example:

– Total pieces complete = 15,000 pieces
– Total scrapped & reworked = 200 pieces
– Total good pieces = 14,800 pieces

This results in a quality score of 98%.

The final OEE result in the example above is 80%, world class OEE is considered to be 85% or greater. In an effort to improve OEE results it is important to understand ‘why’ production fell short. There are six primary reasons for lower than expected results, including: breakdowns, setups, short stops, reduced speed, start-up rejects and production rejects.

Promontory Point Partners, LLC has developed an easy to use dashboard that automatically calculates OEE. Simply enter seven data points in the chart below starting with shift length, click the calc button and the results will automatically appear in the highlighted fields provided.