Article 284 10.

For the purposes of an estimate of alpha under paragraph 9, an institution shall ensure that the numerator and denominator are calculated in a manner consistent with the modelling methodology, parameter specifications and portfolio composition. The approach used to estimate α shall be based on the institution's internal capital approach, be well documented and be subject to independent validation. In addition, an institution shall review its estimates of alpha on at least a quarterly basis, and more frequently when the composition of the portfolio varies over time. An institution shall also assess the model risk.