In this section, a high level overview about the OEE calculation in SAP DM is provided. You can find the detailed calculation within some calculation examples on the SAP DM Help Page:https://help.sap.com/docs/sap-digital-manufacturing/insights/oee-calculations.
Consider that the OEE calculation in SAP DM is calculated on Resource and on Work Center level. The calculation has a time frame of shifts or days and is based on the time buckets which are listed below. Time buckets are segments of time used to accurately capture, categorize, and analyze production data. As shown in the image below, these are the OEE Time Buckets used to calculate the OEE in SAP DM:
- Theoretically Available Time (TOT_PRD_TM)
- The total available time (24/7).
- Loading Time (LOADING_TM)
- Theoretically Available Time minus the scheduled production interruptions (SCHED_DOWN), for example, maintenance stops, or shift breaks.
- Net Production Time (NET_PRD_TM)
- Loading Time minus the amount of time that was lost because of unscheduled interruptions of the production (UNSCD_DOWN). It's the amount of time that a resource was actually available for production.
- Operation Time (NET_OPR_TMN)
- The time required to produce the actual quantities (yield and scrap) based on the standard rate (Net Operation Time = Actual Quantities × Standard Rate). In other words, the Net Operating Time is the amount of time that was available for production minus performance loss (SPEED_LOSS). The performance loss represents the additional time that used for production because the actual production speed was slower than the planned speed.
- Value Operating Time (VAL_OPR_TM)
- Expresses how much time was used for the production of good quality items. It is calculated by removing the quality loss (QUAL_LOSS) from the Net Operating Time. The quality loss value is obtained by multiplying the number of poor quality items (scrap) by the designed speed (standard rate).
Below you can see the formulas to calculate the KPIs of Availability, Performance, and Quality using the OEE Time Buckets:
