SustainPro is an EXCEL based software, which provides options for retrofit analysis and performance analysis of a given process. The objective is to perform sustainable process design through SustainPro. The inputs to SustainPro are the mass and the energy balance data that can be collected either from the plant or from process simulations. To perform the retrofit analysis, SustainPro also requires as input, several cost related data (the prices for utilities, the prices for chemicals, etc.). SustainPro is able to read the mass and the energy balance from an EXCEL file generated by a commercial simulator. The EXCEL interface guides the user through the steps of the work-flow (solution steps). After applying all the steps SustainPro gives as output for the retrofit analysis, suggestions for for improving the process being investigated together with calculated values of the sustainability metrics and the safety indices.