Understand performance

The performance efficiency component of OEE measures a system's ability to produce at the target production rate:

Performance = Total Output / Target Output

Entity Performance

In MES, an entity's performance during a time period is based solely on the production reported on the entity only while the entity is in a Runtime utilization state. If multiple work orders are run during the period, producing different items with different unit of measures, the performance calculation is based purely on item production counts with no effort to convert units of measure.

Line Performance

In MES, the performance component of OEE for a line focuses on the Runtime events during a given time period. The system compares the total output as measured by production transactions during the time period to the output that would be expected if the entity or entities were producing at the target production rate while in the Runtime state.

A line’s performance is:

Performance = Actual Production Count / Expected Production Count

Where:

• Actual Production Count is the total number of good units produced on the production entity during the given time period, plus the reject units produced on the production entity and all entities upstream to the production entity. All counts are converted to the unit of measure (UOM) of the line's standard item.

• Expected Production Count is calculated using the following equation:

  Expected Production Count = Duration of the Bottleneck Entities During Runtime x Job Target Production Rate (in batches) x Default Entity Batch Size

If the bottleneck entity is in parallel with other entities in the same line position, then all the entities at that position in the line will be considered. Only durations for which the utilization event’s Is entity enabled when this reason applies? setting is true are included in the calculation. The actual production counts are determined in the same way the production counts are determined for quality (see Understand quality).