Overview

To calculate KPIs such as the availability or efficiency of a machine or plant, the respective times must be used. These can be derived from the MachineryItemState and the MachineryOperationMode. This annex does not define any KPI values. The assumption is, that the KPIs will be calculated application specific, but can be based on those two states. Potentially, more information is needed for calculating specific KPIs.

The following section provides an example interpretation, of how the MachineryOperationMode and MachineryItemState can be used to determine SEMI E10 [5] times. Typically, MachineryItems are scheduled by higher level systems and are not aware how they are scheduled. So, interpretations of SEMI E10 times are typically “Operations time”.

Example interpretation for SEMI E10

The MachineryItemState OutOfService and the MachineryOperationMode Processing can be interpreted as SEMI E10 “Unscheduled Downtime”.

The MachineryItemState NotExecuting and the MachineryOperationMode Setup can be interpreted as SEMI E10 “Engineering time”.

The MachineryItemState NotExecuting and the MachineryOperationMode Processing can be interpreted as SEMI E10 “Standby time”.

The MachineryItemState Executing and the MachineryOperationMode Processing can be interpreted as SEMI E10 “Productive time”.

In this example, the availability of the Machine is calculated according to ISO 22400. For this purpose, the Actual Production Time (APT) and Planned Busy Time (PBT) are required. The APT can be derived from the combination of the MachineryItemState "Executing" and the MachineryOperationMode "Processing". Alternatively, the APT can also be derived from the Semi E10 time "Productive time". The PBT is usually not known to the Machine and is accordingly not provided by this specification.

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Bibliography

[1] ISO 12100:2010, Safety of machinery – General principles for design – Risk assessment and risk reduction

[2] IEC 61499-1:2012, Function Blocks – Part 1: Architecture

[3] OPC 40501-1, UA for Machine Tools Part 1: Machine Monitoring and Job Overview

(http://www.opcfoundation.org/UA/MachineTools/)

[4] OPC 40010-1, OPC UA for Robotics – Part 1: Vertical Integration

(http://www.opcfoundation.org/UA/Robotics/)

[5] SEMI E10, Specification for Definition and Measurement of Equipment Reliability, Availability, and Maintainability (RAM) and Utilization

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