Service Calculation - how are health and risk caclulated?

Products

• DX Operational Intelligence

Issue/Introduction

In service analytics how health and risk calculated. Is there any document about the calculation. Health is described as "Indicates the percentage of devices that are running normally and operational within the service. The health of service is calculated based on the number of available CIs with the total number of CIs." Which alarms effecting calculation (such as spectrum unreachable alarms, From hosts vmware is connected alarms, or robot down alarms?) 

Risk "Indicates the probability of the service going down. Risk is defined as the risk of service becoming unavailable in the near future unless any action is taken on the alarms and configuration items associated with that service. The risk severity value ranges from severe to normal." Is this calculated with just severity or is there any other calculation weighting coefficient? Do disk cpu and memory alarms affect as same as Process alarms or nt service alarms.

 

Environment

Release : 20.2

Component :

Resolution

The alarms that affect the heath are critical alarms for any entity which forms part of the service. So an entity is said to be down if there is a critical alarm raised against it otherwise it is up. The Service health is then calculated as 

 

Service Health = (entities currently running in UP state) / (total number of entities present in the service definition) * 100

 

The risk is not just based on the severity of alarms against entities in a service but also the significance of the entities. The significance of an entity is based on the number of other entities feeding into and out of it. 

 

The risk is then based on the severity on any alarms raised for entities in the service and the significance of the entity on which they are raised. The highest value is take as the risk.