Standard: NFE 60-182 – May 2002

The OEE "Overall Equipment Effectiveness" is the relation, over the same period, between the quantity that could have been produced at the nominal production rate NPTR (while the line was open) and the quantity that was actually produced.

OEE = NPB / NPTR

NPTR = TR /Cth (Cth = time of cycle, inverse of the theoretical speed) so:

OEE = NPBxCth/TR

or OEE of a team = (sum of the theoretical times to produce a real quantity)/(time of taken by the team: 7.5 hours)

For each NPBi : Theoretical time to produce the right quantity Tthi= NPBi/Vthi where Vthi is the theoretical speed corresponding to the job "i".

OEE of a team = (sum of the theoretical times to produce a real quantity)/(time the team is on site)

For each real quantity: Theoretical time to produce the real quantity Qr Tthi= Qri/Vthi where Vthi is the theoretical speed corresponding to job "i"

Achieving an OEE close to 100%: the Daily Performance Management

Other definitions:

 Economic Return Rate: ERR = TU/TT The ERR is the strategic indicator of the use of production means. It enables the organisation strategy of a company to be refined.

 Global Return Rate: GRR= TU / TO The GRR is an industrial organisation productivity indicator. It is an economic indicator that integrates the effective bearing on a production method.

 Performance rate Tp = TN/TF
 Operational availability Do= TF/TR

Steps for measuring OEE :

1. Know the time cycles by operation and by product range
2. Preparation for measurement:
    make a list of line stop causes
    install a barcode system and a barcode error board gather production information
3. Analysis of the registered data:
    identify progress bearings: analysis by frequency of line stop causes;
    analysis of the duration of the line stop causes

An OEE is always less than 100%. If it goes beyond, then your reference times are too high in comparison with reality. An OEE is considered "excellent" when above 95%, "good" between 85% and 95%,"fair" between 80% and 85%, and "bad" below 80%. But it all depends on where you set your standards...