Despite extensive geological investigations, uncertainties in the ground model often remain. The residual risks associated with this during the construction phase cannot generally be estimated precisely enough in advance. Given such boundary conditions the use of the observational method in line with the principles of the Eurocode EC 7 is therefore required. In order to guarantee safe and economical tunnelling, especially in shallow tunnelling projects, it is vital that a qualified geotechnical safety management programme is implemented during the construction phase. Successful implementation of the geotechnical safety management programme during the construction phase is based on the designer completely defining the anticipated behaviour and on constant target-performance comparisons of the system behaviour by an on-site geotechnical engineer. Advanced data evaluation tools and methods support the continuous interpretation of system behaviour, the early detection of deviations and checking the results against warning and alarm criteria. This paper deals with the fundamentals, requirements and demands of such a management system and describes its practical implementation during the construction phase based on specific ÖBB-Infrastruktur AG project case histories.