Systems and methods of chemical process simulation providing improved methods and systems for expressing the composition of a stream in a chemical process model in a manner that is not immediately indicative of the underlying composition, providing for improved accuracy of allocation of a process output stream to the appropriate source(s), avoiding duplication of components or other inaccurate component representations in relation to critical calculations, and improving the operation of a computer or other computing system for performing chemical process modeling and simulation. The systems or methods provide for three distinct layers of interaction, separating mixed species displayed to the user from individual species used in calculations, while providing transformation objects between dataset layers to provide for accurate modeling, calculation, and display.