OEE stands for ‘Overall Equipment Efficiency‘. These reports are required in manufacturing companies to track the machine efficiency and performance in terms of quality and availability.
The efficiency is measured per line (machine) or per material.
OEE calculation has three different metrics: availability, performance and quality.
Generally, OEE is reviewed on a weekly basis as KPI.
Most important, OEE is used to analyze the reason of losses at any moment in time. If OEE is below target or if a trend is declining, this will be the subject for further investigation.
A machine should be available for work. If it is not due to certain reasons like maintenance, this is recorded as a downtime.
Machine downtime may cause delays in production.
Certain threshold time is defined e.g. 5 minutes. If a machine is not running for more than this threshold time, it is recorded as downtime.
The reason for downtime like idle, breakdown, no input (restraint) etc. is also recorded.
Availability Rate = [(Actual Production time) / (Total Production time - Unscheduled time)] * 100
For each production line, a theoretical output is set. The difference between the theoretical and the actual output determines the performance rate of the machine.
The decrease in performance rate may be due to machine not performing at optimal rates, lot of scrap produced or rework. Any significant reduction in performance rate of the machine need to be examine closely – it may require machine replacement or other such measures.
Performance Rate = [Actual output / Theoretical output] * 100
The performance rate analysis above will reveal the quality of the machines and also poor quality produced due to scrap and rework. This metrics is calculated separately.
Quality rate = [Good Output / Actual Output ] * 100
OEE = Availability rate * Performance Rate * Quality Rate
The MII hub application is used to record these details for each material. This can be an Access database. Every plant has to save this data.
For short term and history trend reports, MII data is fed to BW. The tools like business objects can be utilized to create user friendly and visually appealing reports.
Various trend reports can be analysed showing the daily, weekly and monthly downtime, performance and quality. There reports can be utilized by plant managers and operators to take short term and long term decisions.