Born in Leopoldsburg. Stockmans studied sculpture and ceramics in Hasselt and in Selb in Germany. After graduation he settled in Genk.
From 1966 to 1989 Stockmans was industrial designer in porcelain factory Royal Mosa in Maastricht. In those years he was the chief designer, who designed over 70% of all the companies products. Most successful was his design for the coffee cup "Sonja," of which over 40 million were sold.
Between 1969 and 1998 Stockman also taught industrial design at the Department of product design at the Municipal Institute of Visual Comm and Design, later Media & Design Academy in Genk, and from 1983 to 1985 teacher ceramic design at the Design Academy Eindhoven. Since 1989 he has been a freelance designer.
Since 2010 Stockmans lives on the C-Mine site, a former coal-mine complex near to Winterslag in Genk. In autumn 2010 at the Design Museum in Ghent there was to see a retrospective of his work.