From a process simulation point of view, predicting mixture isotherms using IAST requires more CPU time than using a method that provides the mixture isotherm in an analytical form (e.g., DSL). This can be problematic, i.e., very computationally expensive, if one needs to optimize the process. Possibilities to address the CPU issue include fitting the IAST mixture predictions to an analytical expression or pre-computing the mixture isotherm on a grid and using interpolation techniques.