Weekly OEE Calculation Plan

Summary

• Discussion explains Overall Equipment Effectiveness (OEE) concept and formula.
• OEE is product of three percentage factors: Availability, Performance, Quality.
• Team agrees to compute weekly OEE for provided Gear 6A / broaching data (week 1 and week 3).
• Assignment: calculate Availability, Performance, Quality, then multiply for OEE.

Availability

• Definition: (Planned production time minus lost time) / Planned production time.
• In dataset, time units tracked as shifts (not hours); use shifts as denominator.
• Unplanned loss equals shifts with breakdown maintenance (marked in red).
• Do not count planned changeovers or planned maintenance as lost availability.
• Availability formula for this data: (Planned shifts excluding planned changeovers/maintenance minus breakdown shifts) / Planned shifts excluding planned changeovers/maintenance.
• Availability is binary per shift (either full or lost if breakdown occurs).

Performance

• Definition: Actual production output relative to the theoretical maximum possible output given available input.
• Compute weekly: sum of actual produced units (at broaching output) / sum of planned units for the same period.
• For a shift example: if broaching receives 390 input when theoretical capacity is 400, performance = 390 / 400.
• Performance is assigned to production/shift operations responsibility.

Quality

• Definition: Good output proportion after accounting for scrap.
• Compute as (Good units produced) / (Units that entered the operation or produced before scrap), e.g., 383 / 390 in example.
• Together with Performance, Quality multiplies to give overall yield relative to theoretical max (e.g., 383 / 400 equals combined effect).

Calculation Guidelines / Method

• Work at weekly aggregation (week 1, week 3).
• Use broaching output as the stage for measuring Performance and Quality.
• Steps:
  • Determine planned shifts (exclude planned changeovers/maintenance).
  • Count shifts lost to breakdown maintenance for Availability.
  • Sum actual produced units and planned units for Performance.
  • Compute scrap/good units ratio for Quality.
  • Multiply Availability * Performance * Quality to get OEE for each week.
• Note: Example ballpark—three 90% factors yield ~72% OEE (0.9 * 0.9 * 0.9 ≈ 0.729).

Action Items

• (ASAP – Team) Calculate Availability, Performance, Quality, and OEE for week 1 using provided data.
• (ASAP – Team) Repeat calculations for week 3 using provided data.
• (TBD – Team) Verify assumptions about shift length (assumed 8 hours) if needed; shift-length cancels out when using shift counts.
• (TBD – Team) Confirm treatment of zero-production shifts without breakdown (count under Performance, not Availability).

Decisions

• Use shifts instead of hours for Availability due to dataset.
• Exclude planned changeovers/maintenance from Availability denominator.
• Attribute zero-production shifts (machine available but produced 0) to Performance losses, not Availability.
• Measure Performance and Quality at broaching output, aggregated weekly.

Open Questions

• Should shift length be standardized (8 vs 12 hours) for any additional analyses that require hours?
• Confirm whether any dataset entries labeled as planned maintenance should be excluded from planned shifts count.
• Verify edge cases: how to treat shifts with partial production (partial shift downtime) in shift-based aggregation.