Impact rules Impact rules, which are used for impact calculation, estimate the magnitude or severity of an outage based on affected CIs. The Impact Rule [em_impact_rule] table contains impact rules that show the applicable CIs, business services, and settings for impact. The following default impact rules are available. Host in Cluster Determines how host cluster members affect the overall cluster status based on a percentage or number of cluster members. For example, if a three-host cluster requires 50% Influence to set the severity of Major, each member has 17% Influence (50% divided by 3). The severity of the entire cluster can only change to Major when two or more cluster members have a severity of Major. The entire cluster is also considered to be down. Cluster Member Influence Determines how application cluster members affect the overall impact of the cluster. For example, if a three-member cluster requires 70% Influence to set the severity for the entire cluster to Major, each member has 23% Influence (70% divided by 3). The severity of the entire cluster can only change to Major when all three members have a severity of Major. Inclusion Determines the impact on entities with a Contains relationship. This rule is read-only. Containment Determines the definition of impact propagation for CIs in infrastructure relationships. CI Business Service Determines how impact applies to parent or child entities that are part of a business service. CI Parent in Application Sets impact only on the parent entity. Network Path Determines how impact applies to parent or child entities that are part of a traditional network. Storage Path Determines how impact applies to parent or child entities that are part of a storage network. Service Members Applies to manual services. Determines the relationship between service members. The impact from child to parent CIs is always 100%. For example, the parent impact severity is derived from the child CI with the highest severity.