Aspen HYSYS V7.3 (part of the aspenONE V7.3 engineering suite) is a specialized process simulation software primarily used in the oil and gas, refining, and chemical industries. Originally released around May 2011, this version introduced several key enhancements aimed at optimizing refinery operations and energy efficiency. Key Features of Version 7.3 Refinery Assay Management : Introduced a new Assay Library