Standard for Definition and Measurement of Equipment Reliability, Availability, and Maintainability (RAM) and Utilization Updated
By Michelle Sun, SEMI
SEMI E10, Specification for Definition and Measurement of Equipment Reliability, Availability, and Maintainability (RAM) and Utilization, establishes a common basis for communication between users and suppliers of manufacturing equipment in the semiconductor and related industries by providing a standardized methodology for measuring reliability, availability, and maintainability (RAM) and utilization performance of equipment in a manufacturing environment.
A frequent request from industry was to provide more metrics for critical subsystems in several different types of equipment systems, in addition to noncluster tools, single path cluster tools (SPCTs), and individual equipment modules. Therefore, a new category of RAM metrics, primarily intended for subsystems beyond the current time-based and cycle-based metrics, has been added for other ‘work’ factors (e.g., RF-hours for RF generators, pulse counts for pulse-based excimer lasers in exposure equipment). Examples of other updates include clarification/revisions of several terms (e.g., Unscheduled Downtime State [UDT]), clarification on user-defined substates, and various editorial changes.
SEMI E79, Specification for Definition and Measurement of Equipment Productivity, was also updated to improve the consistency of certain terms, particularly ‘equipment state’. Additional terms were also added to synchronize with terms in SEMI E10.
The next revisions of SEMI E10 and E79 will clarify the definitions for consumable vs. non-consumable parts and the time frame referenced. For SEMI E10, there are also plans to clarify the reliability Extended Growth Model and introduce new terminology to describe the advanced notice model and new terms for predictive and prescriptive maintenance.
This activity is headed by the Equipment RAMP Metrics Task Force, which seeks to provide a unified and consistent set of equipment performance metrics, including RAM, utilization, and productivity.
The new revision is now available for purchase on the SEMI website or SEMIViews.
Get Involved
SEMI Standards development activities take place throughout the year in all major manufacturing regions. To get involved, join the SEMI International Standards Program at: www.semi.org/standardsmembership.
For more information, please visit our main Web site and current events page. If you have any questions regarding SEMI Standards activities, please contact your local SEMI Standards staff.
Standards Watch
SEMI
www.semi.org
March 11, 2021