This chapter describes the analysation of the system behaviour in situ and if possible, in real time, under consideration of all interactions between ground and construction process. It includes the behaviour of the system resulting from the ground and tunnelling process. The new versions of ÖNORM EN 1997‐1 (Eurocode 7) 226 and DIN 1054 74 prescribe the observation method for complex geotechnical structures. The chapter describes the partial processes of the shield tunnelling machine and their interaction for the example of an earth pressure balance shield. It describes data management, which is the most important element of a process controlling system and includes the entire reporting and all essential indicators for design and construction. The chapter deals with target‐actual comparison considering all significant process‐related and geotechnical parameters. The computer‐based results are compared with the design specification, and made available to the responsible geotechnical specialists in evaluated and visualised form.