Dr. Stefan Klessmann studied Information Science, Religion Science and Philosophy at the FU Berlin and Liberal Studies and Museums Management at New York University in the 1980s. He worked for more than 25 years as CFO and managing director of Triad Berlin, an exhibition design office based in Berlin with up to 200 employees. He was involved in about 300 exhibition projects in many countries. This included museums, science centers, visitor centers, Expo pavillons, temporary exhibitions the same as trade fair exhibitions and show room projects. 

Since 2016 Stefan works as an independent consultant for museums, exhibition spaces and visitor centers. The main focus is expansion or redevelopment projects, new museums, cost calculations, evaluations and assessments the same as tendering exhibition projects in the EU according EU rules. Another focus is contracting of exhibition designers.

Since publishing the German HOAS (the initital basis of the SFED) Stefan provided also workshops for design agencies the same as for museums and their procurement departments.