(16)In relation to the internal default risk model, and more in particular Articles 325bn, 325bo, 325bp of Regulation (EU) No 575/2013, it is necessary that the assessment methodology ensures that those risk models lead to accurate results. The rules laid down in the assessment methodology should therefore cover all aspects affecting the outcome of those models, including the scope of the positions captured by those models, the estimates of default probabilities and losses given default, the choice of systematic risk factors to simulate the default of issuers, and all modelling assumptions made by the institution, including any copula assumption made for simulating the default of multiple issuers.