ESIS Technical Committees work on different aspects of Structural Integrity matters. They are the most important part of the ESIS organisation. Their activities are supported by ESIS. The strength of each TC is indicated by the number and scientific quality of Committee members together with their output in terms of reports, recommendations, procedure documents, Special Technical Publications and the regularity of their technical meetings. Wherever possible the subject area of a TC should involve interdisciplinary aspects. Each TC may be split into a number of subcommittees, each examining specific aspects of the main subject area.