The ESTEP working groups are the core element of ESTEP providing the main contributions to ESTEPs outcome. The scope of ESTEPs stakeholders is divided among seven working groups and more and more often activities are carried out by  a collaboration between the working groups. The diagram sumarises this ESTEP approach by showing ist working groups on the left and the scope of the working groups on the right, while several cross-working-topics can be envisaged in the grey circles. Needless to state that all ESTEP activities are within the scope of its strategic research agenda (SRA).