The first churn concept can be used to model the churn of customers from one technology (i.e., Resource) to another, capturing the cost of the subsequent redundancy of Resources.
If you want to model the effect of customer churn on Resource Requirements in a Service, e.g., the case where a Resource is becoming redundant and should be replaced by another following customer churn, you specify a Resource Churn Proportion in the Service / Requirements dialog.
Churn Proportion
Churn proportion represents the proportion of Service demand, allocated to a particular Resource, which is churned every year and has to be reallocated as if it were new demand, according to the current Resource Requirements. This can be used in conjunction with early decommissioning to remove the units of Resources that become redundant as customers churn to another technology.