Skip to main content
Cartegraph Campus

OCI Types and Calculations

The Overall Condition Index (OCI) is a number between 100 and 0 which represents the condition of an asset, 100 being the best and 0 being the worst. The minimum condition is used to calculate the asset’s failure point. Tracking the condition of your assets provides data to help make decisions about things like:

  • budget creation and justification
  • project planning
  • equipment replacement
  • inspection schedules
  • preventative maintenance plans.

Inspections should have data for every condition category with weights, impacts, and a performance curve.

Types

There are two types of OCI calculations—Estimated and Inspected.

Estimated OCI

The estimated OCI for an asset is calculated by taking into account the asset's age, predicted performance, and inspections and tasks performed on the asset. Using this data, the estimated OCI for the asset is determined. Click here for an example.

For assets that do not have an install or replaced date, the oldest completed inspection is used to determine the asset's age.

For the most accurate calculations, we recommend assets have as many of these options as possible in place:

  • Install, replace, or inspection date
  • Fall into a prediction group
  • Set a weight, impacts, and performance curve on each condition category library.

Inspected OCI

During an inspection, a field worker performs an assessment of an asset's condition, which is used to calculate the Inspected OCI. The inspected OCI is a weighted average of the inspection's condition category indexes. Tasks with an Inspect type activity contain an inspection record. When the inspection is complete, the Inspected OCI is calculated for the date of the inspection. It is a best practice to fill out an index for every condition category on an inspection.

Calculation Details

The Weight, or relative importance of an Index, is stored in the Condition Category library. The OCI is the result of dividing the sum of the weighted condition category indexes by the sum of the weights used.

Condition Category

Weight

Index

Result

Aesthetics

2 x

40

80

Structures

5 x

60

300

Surface

3 x

40

120

 

 

 

 

Weighted Sum Total

10

Results Total

500/10

OCI =

500/10

Total OCI is

50

Use higher weight values to increase the relative importance of a Condition Category when calculating OCI. Use lower weight values to decrease the relative importance of a Condition Category when calculating OCI. Null or zero values in Index or Weight have special effects on OCI.

If the Index is

If the Weight is

Effect on OCI

NI(Not inspected)

a number

Estimated index for Condition Category used to calculate OCI. If unavailable estimate, Condition Category is not used to calculate OCI.

0

a number

Index of 0 used to calculated OCI

a number

NULL

Condition Category not used to calculate OCI

a number

0

Condition Category not used to calculate OCI

Once the OCI is calculated, the value is used to look up the corresponding Overall Condition Rating (OCR) stored in the Condition Categories Ratings library.