9-9.3 Relationship of Criticality, Recovery-Time Objective, and Recovery-Point Objective

9-9.3.1 Criticality

The initial determination of criticality of an information resource is determined during the BIA process. Subsequently, internal and external dependencies must be identified to understand how a given application interfaces with the rest of the Postal Service applications and infrastructure. A system is dependent if it cannot function without the input or connection to the other system or portal. For example, applications which by themselves are not critical may have a higher designation because they provide data to an application with a higher criticality designation. Any identified dependencies may change the initial criticality designation.

The criticality determination may be further refined by Postal Service management. The criticality designation will be updated in the BIA and EIR by the Business Continuity Group.

9-9.3.2 Recovery-Time Objective

The RTO, which is the maximum allowable downtime for an information resource, is determined for information resource designated as critical. The RTO is the length of time it takes to restore the information resource. The RTO does not indicate how much data will be lost.

The RTO must be commensurate with the level of criticality. If there is a significant mismatch between the RTO and the criticality designation, the RTO and criticality designation must be reviewed. As a general rule the more critical the information resource, the lower the RTO. A lower RTO often requires a larger investment in BCM resources, which, in turn, results in higher costs. The RTO is determined in consultation with the DR service provider as the DR strategy is defined.

9-9.3.3 Recovery-Point Objective

Also at this time, the data currency requirements/recovery point objective (RPO) is determined. The RPO indicates the maximum amount of allowable data loss. It is the point in time (age) to which data must be recovered relative to the time of the disaster. It is the size of the window of opportunity for data loss. The amount of data loss is determined by backup methods and frequency of backup transport offsite.