Who benefits from OEE in service centers?

How profitable are the machines and systems on the shop floor in service centers? To answer this question, Overall Equipment Effectiveness (OEE) has been proven to be a key figure for the evaluation of productivity. However, not all employees in production are necessarily familiar with OEE. In order to make a valid assessment, a more comprehensive view is often required.

Many companies consider the overall equipment effectiveness (OEE) to be a key indicator for evaluating the productivity of machines and systems. The key performance indicator forms the basis for a continuous improvement process (CIP) in production and thus enables a sustainable increase in productivity. The calculated OEE indicator also allows different machines and systems to be compared with each other, even if they are operating at different locations.

How is the OEE indicator structured?

Overall equipment effectiveness is basically a combination of three individual key figures. These include the availability and performance of a machine as well as the quality of the goods that are produced on the machine. The OEE indicator is intended to provide information on how long a machine is actually operating within the available time, at what speed the machine is producing within its operating time and how much of the produced goods are rejected in terms of quality.

In order to increase the informative value of the individual key figures, they can be further subdivided as required. This way, for example, planned downtimes - such as the set-up or maintenance of machines and systems - can be distinguished from unplanned downtimes and considered separately in the evaluation.

For whom is the OEE key figure relevant?

The OEE indicator as a method of evaluating the productivity of machines and systems in service centers is primarily relevant at management level. The decision to purchase a new machine is usually accompanied by high costs. Once the investment has been made, you want to be able to assess whether the machine is working efficiently and profitably. The OEE indicator offers a suitable approach for such an assessment.

From the point of view of the employees on the shop floor, however, the OEE indicator alone is not very informative. In order to better understand their own work on the machine and identify potential for optimization, practical KPIs are required at this point. These can be, for example, nominal/actual comparisons of the production quantity to be achieved within a shift and the quantity that is actually produced by the end of the shift. When working on a slitting line, it is often much more important in this respect that the machine operators have an overview of the meters of material processed and not just the weight. With regard to the set-up time of the machines before processing an order, a comparison of the targeted set-up time with the actual set-up time required can also provide information on which processes and procedures, for example in the preparatory work steps, can be designed more efficiently.

Complementing OEE with IIoT in a useful way

In order to assess the productivity of machines and systems in service centers in a useful and comprehensive manner, it is important to consider the OEE indicator in combination with other KPIs. Detailed knowledge of the production orders and their structural data is essential for this.

An Industrial Internet of Things platform such as the IIoT and MES platform toii® developed by thyssenkrupp Materials IoT provides the necessary database to achieve complete transparency in production. It enables digital communication in real time between all technical devices and employees in production. This makes it easy to supplement automatically recorded machine data with manually collected data from employees. This way, the specified target value for the three factors of the OEE KPI can be enhanced with additional information and dynamically adapted to the production order data. Downtimes that have a direct influence on the availability factor can be qualified by employees and automatically included in the calculation of the OEE if they are suitably qualified. The OEE for the quality factor is to some extent even calculated live on the basis of real-time data. A concrete recalculation of the actual quotient of the material supplied and the quantity used is also carried out after weighing.