Empirical correlations in mechanistic models make them data-sensitive. This study proposes a systematic method for replacing alternative empirical correlations in a mechanistic model with the view of optimising or simplifying the model, and suggests that current industry practice needs to be changed to first test the data fit of the empirical correlations, before selecting the appropriate mechanistic model. The method is demonstrated on a widely-used model for two-phase slug flow, relevant to petroleum production
