Example - Worst Child Rule

public void calculateKPI(CI ci, KPI kpi) {
    // Get the calculated KPI's type ID (as defined in the Service Health KPI Repository).
    int kpiId = kpi.getType();
    // Get a list of all of the KPIs of the calculated CI's child CIs, which are of the same
    // type as the calculated KPI.
    List<KPI> childKpiList = ci.getChildrenKPIsByID(kpiId);
    // Create a variable to set the status of the calculated KPI, 
    // only if an active status is found.
    boolean isActiveStatusFound = false;
    // Set the current worst status to OK; if a worse status is found this will be updated.
    Status worstStatus = Status.OK;
    // Go over the list of child KPIs.
    childKpiList.each{KPI childKPI->
        // Get the child KPI's status. 
        Status childKpiStatus = childKPI.status;
        // Check if the child KPI's status is an active status.
        if(childKpiStatus.isActive()){
            // Mark that an active status was found.
            isActiveStatusFound = true;
            // Check if the child KPI's status is worse than the current worst status.
            if(childKpiStatus.isWorse(worstStatus)){
                // Update the worst status.
                worstStatus = childKpiStatus;
            }
        }
    }
    // Check if an active status was found in the child KPI.
    if(isActiveStatusFound){
        // Set the calculated KPI status.
        kpi.setStatus(worstStatus);
    }
}