Below is an example of how Estimated OCI (Overall Condition Index) is calculated.
An asset is 2 years old and belongs to Prediction Group Sample B.
The age of the asset is used to calculate its estimated OCI based on expected performance data for the prediction group it belongs to. In this case, the Condition Index for year 2 is calculated as 85. A copy of this performance curve exists for each individual asset record because the curve can shift based on the tasks completed for that asset.
An asset’s estimated OCI is adjusted based on inspection results. If an inspection was completed since the asset was installed or replaced and the inspection has a different condition index than predicted by the curve, the curve shifts vertically so that the actual inspection index lines up with the date of the inspection. The curve will shift up if the inspection index is higher than the estimated index or will shift down if the inspection index is lower than the estimated index.
In the previous illustration. the performance curve estimated the index for year 2 at 85. An inspection in year 2 showed that the inspected index was 90. The curve was shifted upward, indicated by the red arrow with the solid orange line. The estimated condition uses the After Inspection line for the index value. So when the asset is 4 years old, its estimated OCI will be 80, not 75, if no other activities occur.
Additional adjustments to the index are made based on the impacts of completed activities that occurred after the inspection.
The asset continues to age according to the After Inspection line, indicated by the arrow with the dotted red line in the previous figure. In this case, it ages from 90 in year 2 to 85 in year 3.
A task with an impact activity occurred in year 3. The After Maintenance index (indicated by a cyan line) shifts the curve again based on the Impact identified for the activity for the Condition Category. In this case, the index is improved to 100. This shift is indicated by the arrow with the dashed red line.
The After Maintenance curve is used to determine the estimated condition. So in year 5, the asset will again have an estimated OCI of 90.
The calculations above are performed for each condition category. An estimated OCI is calculated for the asset based on the weighted average of the condition categories. Expected performance is calculated until the asset reaches an estimated condition of 0. The date when the OCI drops below the minimum index displays in the Act Before field.
- Prediction Group and Condition Group information is accessible from Asset Condition Manager.
- Since the estimated OCI is a weighted average of all condition indexes for that date, estimated OCI is not calculated if the asset does not belong to a prediction group.
- The Act Before field displays the date the asset’s OCI goes below the minimum index for the condition group the asset belongs to. A value does not calculate if the asset does not belong to a condition group or a prediction group.