Even on that timetable, the regulatory community recognizes that substantial data limitations may prevent banks from developing viable and robust parameter estimates in the near term - even for probability of default in some cases. For this reason, both banks and their supervisors will have to wait while data accumulate before banks can estimate and validate parameter inputs in a reliable, robust manner.
In the interim, banks and supervisors will have to rely heavily on qualitative validation approaches although not entirely. Supervisors across countries are working together to address validation issues, and, I believe, will develop useful guidelines for banks and supervisors alike.