What is impacting your OEE today? Manufacturing systems have many challenges such as unplanned downtime, safety incidents, product quality issues, poor workflow performance and outdated business processes, all of which are further impacted by a changing workforce of retiring and new operators. These issues can have a significant impact on the manufacturing productivity and must be analyzed and measured in order to fully understand the impact of each item. Identifying these issues often bring to light the effectiveness level of key operational resources and thus opportunities for operational improvements in cost and productivity.
Overall Equipment Efficiency or OEE, is measured as a percentage by multiplying Availability by Efficiency by Quality. It is one of the top five most widely accepted measures of Operational Excellence. However, there are multiple metrics to measure availability, efficiency and quality. Lack of a standard metrics makes it harder to drive improvement across the plant. Standardizing the measurement methods for the various data points that contribute to the OEE calculation across the manufacturing enterprise will increase visibility when analyzing assets at the equipment level, line level and plant level.
Measuring Availability: In the three elements of the equation, Availability is one that creates the most discrepancy between manufacturers and within companies. One of the most effective methods of measure of Availability is based on demand, rather than theoretical production of 24×7. Therefore, the recommended calculation is: Availability = Asset Uptime X Asset Scheduled Production Time.
Measuring Efficiency: Many companies base the calculation on MRP attainment levels which oftentimes lead to manipulation of production numbers in order to keep efficiency in line with production. The most realistic method for measuring efficiency is based on engineering or OEM estimates. This recommended calculation is: Efficiency = Total amount of product produced / (Time asset was available X Theoretical maximum production rate of asset).
Measuring Quality: The most easily calculated element of the OEE equation is Quality. However, methods of measure vary between using Overall Yield and First Pass as the standard. While using overall yield focuses on areas for improvement, this metric provides the opportunity for rework and dilutes the value of the OEE equation. Using First Pass is a more accurate measure providing the calculation: Quality = Total products achieving quality first time / Total products produced.
Applying a sound manufacturing intelligence methodology to help standardize the OEE metrics to Measure Availability – Measure Efficiency – Measure Quality will create visibility in your operation. Automating your business processes brings consistency and performance to your plant leading to continuous improvement and operational excellence.