What scenario would allow for a smaller sample size in a PCI DSS assessment across multiple facilities?

A smaller sample size in a PCI DSS assessment across multiple facilities can be justified when security policies are standardized for each region. This standardization ensures that all facilities within the same region implement security measures that are uniform and consistent. As a result, when assessing compliance with the PCI DSS, the assessor can focus on a representative sample, confident that the same policies and procedures are in place across the facilities being sampled. This reduces variability and potential discrepancies that might arise if each facility had different security practices.

In cases where security policies are defined independently by each facility or where each facility creates its own procedures, the assessor would need to evaluate a larger sample size to account for the differences, which complicates the assessment process. While centralized policies alone can help standardize some aspects, if they're not consistently implemented at each facility, it would still necessitate a broader sample to ensure accurate compliance verification. Therefore, having standardized policies specific to each region provides the necessary foundation for a more efficient and effective compliance assessment with a reduced sample size.