There are four steps to the CRM Calculation, whether at direct or look-through level:

STEP 1Calculate the Credit Risk
STEP 2Map the Credit Risk to the unadjusted Credit Quality Step (CQS)
STEP 3Calculate the adjusted Credit Quality Step (CQS) to reflect the maturity or the recommended holding period.
STEP 4Convert the adjusted Credit Quality Steps to the CRM

The method for calculating the MRM is set out in Delegated regulation 2017/653 at Annex II, Part 2.