The focus of this publication will be to demonstrate how to use a process simulation package to successfully design a distillation column. The authors will present two test cases: a methanol and water system and a benzene, toluene, and cumene system These systems will be used to demonstrate the steps to obtain a good design using a process simulation package. First, equilibrium data results from the simulation will be compared to the literature data. The equilibrium data will be compared to results obtained from three commercial process simulation packages. Once the equilibrium data from the simulations have been determined to be reasonable, a step-by-step procedure will be provided demonstrating how to make sure your simulation results provide a successful design. These steps will be based on steps using graphical analysis techniques to evaluate simulation results. Finally, the authors will provide guidelines to select the correct mass transfer internals for the above mentioned design cases.