The OEE (Overall Equipment Effectiveness) is the product of Availability, Effectiveness and Quality Rate. These measures are calculated as follows:
Availability = APT / PBT
Effectiveness = PRI x PQ / APT
Quality rate = GQ / PQ
In addition to the indicators APT, PQand GQas previously defined, the planned variables PBT(Planned busy time) and PRI(Planned run time per item) are required. This information usually comes from an MES or ERP and not from the machine, so it has not been included in this specification. To calculate the OEE, this information must therefore be determined from the connected MES or ERP.
 ISO 22400-2: 2014. Automation systems and integration–Key performance indicators (KPIs) for manufacturing operations management–Part, 2
 OPC 40001-1, OPC UA for Machinery – Part 1: Basic Building Blocks