Introduction to OEE

Overall Equipment Effectiveness (OEE) is a standard performance metric—a tool that objectively measures your production by the performance of your equipment and your personnel. In Plant Applications, OEE measurement can:

• Help you reduce the gap between actual production and what your operations are capable of producing

• Help you "drill down" into areas where improvements can be made, allowing you to increase production uptime, throughput, and quality

The ultimate goal in efficiency management is to achieve 100% in quality, speed, and uptime in your operation. But how do you measure where you are at now, relative to that goal?

OEE rolls up a number of perspectives into a single figure, and provides an easy way to measure efficiency—you can analyze a machine's or a line's efficiency over time, compare it with like units on the same line or in the same plant, or compare your operation to another. Plant Applications' OEE adds the advantage of letting you drill down into your processes in order to discover where improvements can be made.

A small improvement in OEE can mean tremendous savings over time. For instance, if a pulp mill that produces 2000 tons per day improves its OEE by just 1%, it could realize a savings of $2.8M per year (if pulp is $450/ton).

OEE = Availability X Performance X Quality

At its core, OEE combines three separate metrics that measure equipment availability, performance, and quality ("quality" refers to equipment's ability to produce "first-time-right" product). Once these metrics are derived, they are multiplied to arrive at the OEE result, which is a single number expressed as a percentage.

Availability refers to the uptime of equipment during a period for which it is scheduled to run. An availability rate of 100% indicates that the equipment suffered no unplanned downtime.

Performance measures the speed at which the equipment operates, as compared with the speed at which it was designed by its manufacturer to run, or with the results of an engineering department's efforts to increase design speed through retrofits, etc. A performance rate of 100% indicates that the equipment ran at 100% of design speed. In theory, performance speed can never exceed 100%. If it does, then the design speed specification is too low, and should be adjusted accordingly.

Plant Applications takes this fact into consideration in its Performance Calculation and "caps" performance rates at 100% if they exceed this. If your reports constantly show Performance Rates at 100%, then it may be an indication that your design rate targets are too low, should be analyzed and adjusted upwards.

Quality measures the percentage of "first-time-right" products produced by the equipment, as compared with the total amount (gross production) of product it produced. A quality rate of 100% indicates that the equipment operated at a 0% defect rate.

Generic OEE Benchmarks

OEE is a relative measure, used to gauge improvement or decline in overall equipment effectiveness over time. For example, if one week OEE on a given unit is 73%, and on the next week it is 75%, then the overall effectiveness of the unit has shown improvement. While you will generally find the best use of OEE in this manner, the following table shows some generic OEE reference points, typical across many industries:

See also

Time Categorization

OEE Configuration Overview

OEE Deliverables