An automated code comparison is the process of comparing two versions of the same program to determine whether the two correspond. It is an efficient technique because it is an automated procedure. Test data runs permit the auditor to verify the processing of preselected transactions, but provide no evidence about unexercised portions of a program. Code review is the process of reading program source code listings to determine whether the code contains potential errors or inefficient statements.A code review can be used as a means of code comparison but it is inefficient. The review of code migration procedures would not detect program changes.

The most important prerequisite for the protection of physical information assets in a data center is a complete and accurate list of information assets that have been deployed. Information assets are any data, devices, systems, or software that have value for the organization and need to be protected from unauthorized access, use, disclosure, modification, or destruction4. A data center is a facility that houses various infor mation assets such as servers, storage devices, network equipment, etc., that support the organization's IT operations and services5. A complete and accurate list of information assets that have been deployed in a data center can help to identify and classify the assets based on their importance, sensitivity, or criticality for the organization. This can help to determine the appropriate level of protection and security measures that need to be applied to each asset. A complete and accurate list of information assets can also help to track and monitor the location, status, ownership, usage, configuration, maintenance, etc., of each asset. This can help to prevent or detect any unauthorized or inappropriate changes or movements of assets that may compromise their security or integrity. Segregation of duties between staff ordering and staff receiving information assets, availability and testing of onsite backup generators, and knowledge of the IT staff regarding data protection requirements are also important prerequisites for the protection of physical information assets in a data center, but not as important as a complete and accurate list of information assets that have been deployed.
These factors are more related to the implementation and maintenance of security controls and procedures that depend on having a complete and accurate list of information assets as a starting point. References:
ISACA CISA Review Manual 27th Edition, page 308