gPROMS is a mathematical modelling platform that combines state-of-the-art detailed modelling with the ease of customized flowsheeting, while being able to do dynamic optimization, parameter estimation and design of experiments. Furthermore, PSE can handle consultancy all the way from complete process and operation design done by PSE to the customer doing most of the work and calling in support. The customization together with superior mathematical solvers makes gPROMS the choice of many companies in many different areas, from base chemicals, to bio-engineering, pharma, surfactants, paper, cement etc.