The SBR for an object is created from the most reliable information contained in each system record representing that object. The information used from each external system to populate the SBR is determined by the survivor calculator, which is configured in the Best Record file. This data is determined to be the most reliable information from all system records in the enterprise record. The survivor calculator can consider factors such as the relative reliability of an external system, how recent the data is, and whether the SBR contains any “locked” field values. You define the rules that select a field value to be persisted in the SBR.