From the founding of the IAKS, Roswitha Thibes was Frieder Roskam's right hand. As the Manager of the IAKS, she was responsible for the organisation of the Office, staffing, finance and accounting until 2002.
Thibes was involved in the organisation and staging of the IAKS Congresses for many years. She served Executive Board meetings and the IAKS sections and handled membership issues. From 1978 to 1995, she was also editor of the IAKS magazine "sb".