The OEE Metric View indicates how well a manufacturing unit is performing by evaluating the total availability, performance, and quality of that production unit and its products. Using the OEE Code field in Production Loss records that are associated with a Production Unit record, the OEE Metric View categorizes the production losses for a given Production Unit into these three categories.
The results are displayed as an overall OEE percentage. A manufacturer's goal is to operate at 100% OEE (or as close to it as possible), which can be accomplished only by achieving 100% availability, 100% performance, and 100% quality. Each production loss categorized by an availability, performance, idle time, or quality OEE code, or a child code of these codes, will subtract from each percentage.
Note: If you have created a custom OEE code, it must be a child of a baseline OEE code (i.e., Availability, Performance, Idle Time, or Quality) in order to be included in the OEE Metric View calculations.
Each level of the OEE Metric View displays the OEE percentage for a production unit during a given time frame (year, month, day), where the time frame is displayed along the x-axis and gets progressively smaller as you drill into the Metric View. The OEE percentage at each level of the Metric View is calculated using the following equation:
OEE (%) = [OEE (Availability) (%) x OEE (Performance) (%) x OEE (Quality) (%)] x 100
This formula can be further divided into three subformulas, where each subformula is used to calculate the percentage of availability, performance, or quality.
For example, we want to measure the OEE of a bottling plant during the month of April. The actual production for the month is 1,000 bottles. The following chart displays the total production loss associated with each OEE code during that month.
Parent OEE Code |
Child OEE Code |
Production Loss Amount |
---|---|---|
Availability |
Scheduled Downtime |
40 |
Availability |
Unscheduled Downtime |
150 |
Performance |
Reduced Rate |
75 |
Performance |
Minor Stops |
77 |
Quality |
Production Rejects |
300 |
Quality |
Startup Rejects |
4 |
To calculate OEE percentage for our bottling process, we must first calculate the availability, performance, and quality percentages using the OEE codes that are assigned to production losses. Each of these subformulas within the OEE calculation has its own corresponding Metric View, which are described below.
OEE (Availability) (%)
OEE (Availability) (%) = (Actual + Performance Losses + Quality Losses) / (Actual + Performance Losses + Quality Losses + Availability Losses)
...where:
Availability Losses = Losses due to Availability + Losses due to Unscheduled Downtime + Losses due to Scheduled Downtime + Losses due to custom child OEE codes with Availability as a parent code
Performance Losses = Losses due to Performance + Losses due to Minor Stops + Losses due to Reduced Rate + Losses due to custom child OEE codes with Performance as a parent code
Quality Losses = Losses due to Quality + Losses due to Production Rejects + Losses due to Startup Rejects + Losses due to custom child OEE codes with Quality as a parent code
For our example, suppose that:
Actual values are 1,000.
Quality Losses are 304 (300 + 4).
Performance Losses are 152 (75 + 77).
Availability Losses are 190 (150 + 40).
In this case, the Availability (%) calculation would look like this:
OEE (Availability) (%) = (1,000 + 152 + 304) / (1,000 + 152 + 304 + 190)
OEE (Availability) (%) = 1,456 / 1,646
OEE (Availability) (%) = 0.88
OEE (Performance) (%)
OEE (Performance) (%) = (Actual + Quality Losses) / (Actual + Quality Losses + Performance Losses)
Where...
Performance Losses = Losses due to Performance + Losses due to Minor Stops + Losses due to Reduced Rate + Losses due to custom child OEE codes with Performance as a parent code
Quality Losses = Losses due to Quality + Losses due to Production Rejects + Losses due to Startup Rejects + Losses due to custom child OEE codes with Quality as a parent code
For our example, Performance Losses are 152 (77 + 75) and Quality Losses are 304 (300 + 4). The Performance (%) calculation would look like this:
OEE (Performance) (%) = (1,000 + 304) / (1,000 + 304 + 152)
OEE (Performance) (%) = 1,304 / 1,456
OEE (Performance) (%) = 0.90
OEE (Quality) (%)
OEE (Quality) (%) = Actual / (Actual + Quality Losses)
Where...
Quality Losses = Losses due to Quality + Losses due to Production Rejects + Losses due to Startup Rejects + Losses due to custom child OEE codes with Quality as a parent code
For our example, Quality Losses are 304(300 + 4). The Quality (%) calculation would look like this:
OEE (Performance) (%) = 1,000 / 1,304
OEE (Performance) (%) = 0.77
OEE (%)
After each subformula has been calculated, we can use those percentages to calculate the overall OEE percentage.
OEE (%) = [OEE (Availability) (%) x OEE (Performance) (%) x OEE (Quality) (%)] x 100
OEE (%) = [ 0.88 x 0.90 x 0.77 ] x 100
OEE (%) = [ 0.61 ] x 100
OEE (%) = 61%
You can use the OEE Metric View to see how well your manufacturing operation is performing. For example, perhaps in 2011, this unit had an OEE percentage of 85% during the month of February. This means that due to a decrease in availability, performance, or quality, the production unit was not 100% efficient. In April, the month we used in our example, OEE dropped to 61%. We may conclude that a change in our production process caused a loss of efficiency, and we should examine the areas of availability, quality, and performance to determine what changes can be made to improve OEE. To see which OEE code was associated with the highest amount of production loss, use the Losses By OEE CodeMetric View.
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