The HYSYS Version 1.1 Reference Volume was published in 1996. HYSYS is able to perform many of the core calculations of chemical. Aspen HYSYS (or simply HYSYS) is a chemical process simulator used to mathematically model chemical processes, from unit operations to full chemical plants and refineries. 12 min - Uploaded by Hassen GhorbelYour browser does not currently recognize any of the video formats available.