Procedure that aims to assess the performance of fitted models and to determine if they can be used to aid decision-making. The validation process might use several hundred of evaluation data to evaluate the model accuracy. It consists of comparing model predictions with independent experimental/observational data though indices of model performance including bias factor, accuracy factor and the acceptable simulation zone approach in combination with graphical methods (Mejlholm et al., 2010; �stergaard et al., 2014).