Overall Equipment Effectiveness (OEE) provides a quantitative metric, based on the elements Availability,
Performance and Quality, for measuring the effectiveness of individual equipment and entire processes. This is
significant but insufficient because not only those three factors have an impact on the overall performance of a
machine or process but also some others such as the efficiency usage of raw materials, their quality and cost, as
well as the environment (e.g. logistics, production system, labour, etc.) where the equipment or process operates.
This paper presents an improved approach, Overall Resource Effectiveness (ORE), which considers those
elements in the overall effectiveness evaluation. The paper shows the logical development of the concept and
formulas used in the calculation of ORE. Then, a practical investigation of this approach is done through a case
study. The case study demonstrates that OEE is not a “generic” measurement system appropriate for all types of
processes as well as the broader perspective and information of performance that can be obtained from the use of
ORE.