This standard was technically approved by the global Metrics Committee. This edition was approved for publication by the global Audits and Reviews Subcommittee on August 24, 2006. It was available at www.semi.org in October 2006 and on CD-ROM in November 2006. Originally published February 1999; previously published March 2005.
The purpose of this specification is to The document provides metrics for measuring equipment productivity.
This specification defines metrics and calculations for measurement of equipment productivity. In the context of this documentspecification, it is important to note that "equipment productivity" is impacted greatly by factors far beyond the equipment itself, including operator actions, recipe settings, facility issuesies, material availability, scheduling requirements, etc. Effective application of this specification requires that equipment performance is tracked using the metrics for eEquipment Reliability, Availability, and Maintainability (RAM) established in SEMI E10. Additionally, the Automated Reliability, Availability, and Maintainability Standard (ARAMS) SEMI E58 can be used for equipment with ARAMS capability.
NOTE : Several terminology changes were made during this revision to harmonize with SEMI E10 including changing fixed-sequence cluster tool to single-path cluster tool and flexible-sequence cluster tool to multi-path cluster tool. Productivity metrics for flexible-sequence multi-path cluster tools require tracking of SEMI E10 equipment states and recipes at the level of individual processing modules.
The Equipment Performance Tracking (EPT) Standard SEMI E116 assists SEMI E79 by providing the status of the major modules of the equipment allowing, which allows the tracking of performance metrics to be tracked at the module level.
SEMI E116 also assists SEMI E79 by providing task-level detail of the equipment or module's current activity, which allows the tracking ofallowing performance metrics to be tracked at the task level. Productivity performance of a flexible-sequencemulti-path cluster tool is then calculated as the aggregate productivity performance of its the multi-path cluster tool's individual processing modules. This document specification is currently limited to measuring equipment productivity using Overall Equipment Efficiency (OEE) as the metric, and does not address the impact of productivity changes on cost, cycle time, or other measures.
This document specification does not address any RAM issues over and above those in SEMI E10.
NOTE : While traditional total productive maintenance (TPM) literature (some examples are given in 7) calculates overall equipment effectiveness (also using the same acronym OEE) based on units of production, overall equipment efficiency (OEE) is the more correct term for the time-based calculations defined in this specification.
Traditional unit-based overall equipment effectiveness calculations and the time-based OEE calculations within this specification yield essentially the same results.