Asset Performance Management concepts
The Asset Health application in IBM® IoT for Energy and Utilities has concepts that are unique to the solution and the energy industry. Understanding these concepts is important to understanding the data presented by the solution.
Asset Health Index
The Asset Health Index indicates the health of an asset and is an aggregation of the measurement results of the condition criteria of an asset and a weighting factor for each of those measurements.
These condition criteria indicate the health status of an asset, and the weight describes the degree of importance given to each. The Asset Health Index returns values in the range 0 to 100 where 100 is as new condition and 0 is very poor condition.
Asset Degradation Curve
The Asset Degradation curve is based on a normal or Poisson distribution: a small percentage of assets fail during the early life and beyond the average expected life span, the majority of fails are within the one std deviation of the mean life. The Asset Degradation Curve is calculated based on historical data collected for failure and retirement of assets. Each asset class has its own asset degradation curve.
Effective Age
The age of an asset is based on the date of commission. The age gives valuable indication of condition but can also lead to early an retirement of a working asset while allowing an overused asset to fail prematurely. To give an effective age, the Asset Health index is used in conjunction with the age to give a more accurate condition based on historical performance and maintenance of the asset.
The effective age emphasizes that maintenance of an aging asset does not renew an asset to an as new condition. At best, well-planned maintenance helps to extend the useful life of an asset but can not revert aging nor prevent end of life.
Similarly, all assets can be maintained for many years but with an increasing difficulty over time. As this is not always the most economic solution, all assets have a definite end-of-life.
Criticality
Criticality is a measure of the importance that an asset is to the network by the relationship between the number of customers an asset supports and the total number of customers that the feeder to the asset supports. Assets that support a greater number of customers in relation to the total number of customers of the feeder have a higher Criticality rating. Criticality is rated from 0 to 100 where 0 is no customers and 100 is all customers.
Failure probability
Failure probability is the probability that a single asset fails in a certain time period.
The effective age of an asset is plotted against the degradation curve of the asset to ascertain the failure probability. This result is the failure probability of the asset in the current year. For future k years, age is defined as (the effective age + k years). The failure probability is read from the degradation curve according to that age.
The higher the failure score, the more likely the asset will fail.
Risk
Risk is the risk to the business due to a failure of an asset in the network. The higher the value for the Risk the more risk there is to the business. Risk is a percentage value given by the product of the values for Failure probability and Criticality divided by 100.
If Failure probability is 30 and Criticality is 65, then Risk is 19.5%. If Criticality is much fewer in terms of customers, then if Failure probability is 30 and Criticality is 10, then Risk is 3%.
Risk returns values in the range 0 to 100 where 0 is no risk and 100 is a very high risk.