Overall net equipment effectiveness

The term net equipment effectiveness (NGE) or English Net Equipment Effectiveness (NEE) describes a key figure . The key figure is based on the OEE (gross overall system effectiveness ). The net overall system effectiveness includes losses that occur in a system and have an impact on production.

The OEE of a plant is defined as the product of the following three factors:

• the degree of utilization (availability)
• the level of performance (Performance Rate)
• the quality rate

Its range of values ​​is between 0 and 1.

The degree of utilization

The degree of utilization is a measure of losses due to system failures. In contrast to the degree of utilization in the OEE, set-up and setup processes are not taken into account. It is defined as follows:

${\displaystyle {\text{Nutzungsgrad}}={\frac {\text{Zeit der Betriebsbereitschaft}}{\text{Planbelegungszeit}}}}$

The operational readiness time is defined as the difference between the planned occupancy time and the time due to system failures. The planned occupancy time is defined according to VDI guideline 3423 as the product of the shift length in hours × number of shifts × number of working days in a month.

The level of performance

The degree of performance is a measure of losses due to deviations from the planned cycle time, minor failures and idle runs.

${\displaystyle {\text{Leistungsgrad}}={\text{Grad der Bearbeitungsgeschwindigkeit}}\cdot {\text{Netto Bearbeitungszeit}}\qquad (1)}$

${\displaystyle {\text{Grad der Bearbeitungsgeschwindigkeit}}={\frac {\text{geplante Taktzeit}}{\text{reale Taktzeit}}}\qquad (2)}$

${\displaystyle {\text{Netto Bearbeitungszeit}}={\frac {{\text{Anzahl produzierter Teile}}\cdot {\text{reale Taktzeit}}}{\text{Maschinenlaufzeit}}}\qquad (3)}$

from (2) and (3) in (1) follows:

${\displaystyle {\text{Leistungsgrad}}={\frac {{\text{geplante Taktzeit}}\cdot {\text{Anzahl produzierter Teile}}}{\text{Maschinenlaufzeit}}}}$

According to REFA , the machine running time is defined as the time in which the machine actually produces, i.e. H. Operating time minus downtime, idle times caused by the flow and idle times.

The quality rate

The quality rate is a measure of the time lost due to defective parts that need to be reworked. It is defined as follows:

${\displaystyle {\text{Qualitätsrate}}={\frac {{\text{Anzahl produzierter Teile}}-{\text{Anzahl Nacharbeitsteile}}-{\text{Anzahl Ausschussteile}}}{\text{Anzahl produzierter Teile}}}}$

Net Equipment Effectiveness

The NEE is defined as the product of degree of utilization, degree of performance and quality rate. If the above formulas are used together, it follows:

${\displaystyle NEE={\frac {{\text{geplante Taktzeit}}\cdot ({\text{produzierte Teile}}-{\text{Anzahl Ausschussteile}}-{\text{Anzahl Nacharbeitsteile}})}{\text{Planbelegungszeit}}}\cdot {\frac {\text{Zeit der Betriebsbereitschaft}}{\text{Maschinenlaufzeit}}}}$

literature

• TPM - Efficient maintenance and machine management, Edward Hartmann, Landsberg, Verlag Moderne Industrie, 2000, ISBN 3478913748 , pp. 77ff.
• Business administration terms for technicians - Montanuniversität Leoben

Individual evidence

1. ↑ BWL terms on wbw.unileoben.ac.at ( Memento of the original dated May 30, 2009 in the Internet Archive ) Info: The archive link was automatically inserted and not yet checked. Please check the original and archive link according to the instructions and then remove this notice. 

OEE Industry Standard (in German)