In this paper a comparative analysis of the most important approaches for integrated WWTP modelling is presented. After an introductory presentation of the most important drawbacks and challenges for plant wide modelling, the fundamentals of three different approaches to construct integrated models are presented: “Interfaces” “Standard Supermodel” and “Tailored Supermodel”. Afterwards, a comparative analysis of these approaches from different points of view (difficulties for the model end user, characterization of the process in the plant, flexibility or adaptability for each case of study, simulation platform requirements and computational costs) is carried out. From this comparison, some important conclusions about the suitability of each alternative depending on the simulation case study are extracted.