Regardless of the industry, companies involved in all types of manufacturing are looking to maximise the efficiency of the production process. Fully harnessing the potential of your machinery is something that can help you improve the productivity of your plant. One of the ways to evaluate how well your factory is using its equipment is to calculate OEE.

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What is OEE?

The OEE (Overall Equipment Effectiveness) indicator is a measure of how well machines involved in a given manufacturing process are used. Whether a machine runs at its maximum possible speed has a direct impact on the truly productive manufacturing time of a product. Equipment that is used inefficiently reduces the competitive edge and the profits of a company.

For this reason, any company that uses machinery in the manufacturing process aims to maximise its efficiency. Each unplanned downtime of a production line generates losses for the plant. Therefore, a number of tools have been developed to improve the organisation of work and thus to increase equipment effectiveness. 

One of these is the TPM (Total Productive Maintenance) system, one element of which is precisely the OEE score, which measures equipment effectiveness as a percentage. This equipment is specifically production lines, groups of machines and individual machines used in the manufacturing process that are a priority for the company. OEE calculation is based on three indicators: availability, performance and quality.

Calculated on the basis of reliable data coming directly from the manufacturing process, and properly interpreted, the OEE score allows optimising plant operations in such a way as to further reduce production time, which directly translates into higher profits from the manufacture and distribution of the product.

How to calculate OEE?

As mentioned above, OEE calculation is carried out on the basis of three indicators, which are in turn calculated using data collected during the production process. These are availability, performance, and quality. The OEE score is the product of these three values, and represents the overall equipment effectiveness of a plant, expressed as a percentage.

Availability is the ratio between the time planned to complete a production task and the truly productive manufacturing time. Availability is reduced by all maintenance activities in the plant, i.e. breakdowns of all kinds, maintenance work, repairs and time spent on line changeovers.

The second index used to calculate OEE is the performance score. Like availability, it is a ratio of two values. Performance compares the machine’s scheduled operating time and the actual operating time in a given period. The performance score is reduced by reduced speed of operation during the production process. Lost productivity means a reduction in the ratio of actual to planned production.

The last value needed for OEE calculation is the quality score. How is it calculated? As with the other two values, it is the ratio of the number of parts that meet quality requirements to the total number of parts produced in a given period of time. As you can easily guess, this score is lowered by a large number of defective parts that do not successfully pass quality control at the production plant.

Utilising OEE in the manufacturing process

The OEE indicator is one of the basic tools for evaluating the performance of a plant. It is used by many companies around the world. OEE helps in the analysis of the production processes in both medium-sized companies and true giants with global reach. Some research sources on production efficiency cite an OEE value of 85% as the “global standard”. But is it really possible to compare ratios between companies operating in different industries and with different production characteristics?

Comparing OEE values between two companies only makes sense if both companies are of similar size and if their production processes are similar. Additionally, both companies would have to collect production data in exactly the same way, which is extremely rare. In practice, the comparison of indicators is only justified if both plants are part of the same company, as then they have similar standardised ways of collecting production data.

For those reasons, the overall equipment effectiveness indicator works best for comparing the situation within a single plant. With the use of a single OEE calculation method and a consistent method of collecting production data, OEE is perfect for comparing whether the efficiency of a machine has improved or deteriorated over successive periods and how production time has changed.

In summary, the value of the OEE indicator is not as important as the factors that cause it to change and the fact that the plant is beginning to notice their impact on the production process. By analysing the changes in the indicator, one can see that sometimes even small changes to the manufacturing process can have a huge impact on the productivity and therefore profits of a company.

OEE indicator – summary

We hope that this article has helped you understand what the OEE indicator is and how it should be calculated. As a reminder, it is one of the most popular ways of analysing efficiency in production facilities. It is calculated as the product of three components: availability, performance, and quality. The result of the calculation of the overall equipment efficiency indicator is given as a percentage.

Keep in mind that the value of the indicator itself is not as important as tracking its changes at regular intervals. On the basis of changes recorded by the OEE indicator, it is possible to learn about the problems that slow down the entire manufacturing process, or to find out whether changes made to improve the efficiency of plant equipment are having the desired effect.

If you would like to equip your production plant with cutting-edge machinery that will enable you to increase the efficiency of your production process, or if you would like to upgrade your current machinery, please feel free to use the contact form that is available on our website at You can be sure that our experienced experts will help you choose a solution that meets all your expectations.