Initially Guardrail Score was 95 for the Application. After performing Major skimming on the Application rulesets Guardrail Score is Dropped to 80, and i pointed the new application version to the new Skimmed rulesets. Is there any reason for dropping of Guardrail Score.
Compliance score is calculated by comparing warnings - weighted by severity and justification- with the number of total rules.
Skimming does not delete any rules. Skimming copies but does not update or delete rules in the source versions. After Skimming, you might have deleted any unused rules which had reduced the total number of rules( the denominator of Compliance score) and ultimately decreased the compliance score.
Please check the total number of rules and number of rules with warnings and the total number of warnings before and after skimming process to see what affected the Compliance score.
Warning Summary and Compliance Score tabs of Application- Guardrails provide you all the above details.