Become a DWSIM Patron and help encouraging the creation of new videos: / dwsim A recent update to the Excel Add-In added the possibility of editing Property Package parameters before making a calculation. This enables the user to fit model parameters to experimental data. In this video, you'll learn how to modify a Methane/Ethane interaction parameter for the Peng-Robinson equation and check the effects of the parameter value in the vapor phase compressibility factor.