Frequently Asked Questions

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How did Prioritized Approach Tool calculations change for PCI DSS v3.2?

FAQ Response

The Prioritized Approach Tool for PCI DSS v3.2 includes an update to the built-in formulas to remove “N/A” (Not Applicable) responses from the Percent Complete calculation. Previously, a response of “N/A” was calculated in the same way as a response of “Yes” (which indicates a requirement is “in place”). The updated calculations are statistically more accurate than previous calculations. However, as “N/A” responses are no longer calculated in the same way as “Yes” responses, this may result in a lower Overall score for non-compliant merchants than the formulas used in previous versions.

As an example: If a Milestone contains 10 PCI DSS requirements, and an entity identifies 5 requirements as “N/A”, 3 requirements a “No” (not in place), and 2 requirements as “Yes” (in place), the resulting calculation would be:

  • For v3.1 of the Prioritized Approach: The calculation considered 7 requirements (the sum of “N/A” and “Yes” responses) as “in place” out of the total 10 requirements, resulting in a score of 70% for that milestone.
  • For v3.2 of the Prioritized Approach: Because the 5 “N/A” responses are excluded from the calculation, there will be 2 requirements (“Yes” responses) identified as “in place” out of the 5 applicable requirements, resulting in a score of 40% for that milestone.

This example calculation is also summarized in the following table:

 

Total Requirements

Requirements identified as “N/A”

Requirements included in calculation

In place

Not in place

Milestone score

PCI DSS v3.1

10

5

10

2

3

70%

PCI DSS v3.2

10

5

5

2

3

40%

 

While this change simplifies and improves accuracy of the calculation process, the result is that a non-compliant merchant may appear to show a “drop” in compliance when using the Prioritized Approach Tool for PCI DSS v3.2 when compared to their report for PCI DSS 3.1 (or earlier), even if they report the same requirements as being in place, not in place, and not applicable.  Organizations and their compliance reporting entities will need to take this into consideration when comparing results from the Prioritized Approach v3.2 to results from previous versions.

Entities that are able to report all applicable PCI DSS controls as being in place will achieve an Overall result of 100%.

March 2017
Article Number 1446