The IRB approach of the Basel Capital Accord provides a single framework by which a given set of risk components or "inputs" are translated into minimum capital requirements. The framework allows for both a foundation method and more advanced methodologies. In the foundation method, banks estimate the probability of default associated with each borrower, and the bank supervisors supply the other inputs. In the advanced methodology, a bank with a sufficiently developed internal capital allocation process is permitted to supply other necessary inputs as well.