Cyber-physical systems offer great advantages in terms of efficiency and quality in production. However, one problem is the detection of manual, analog interventions in digital production systems, as these are often not recorded automatically.\nIn the fused filament fabrication (FFF) process, for example, nozzles are replaced manually. These have a direct influence on the component quality, but usually only their nominal diameter is stored digitally, not which nozzle is installed exactly. However, this would be necessary in order to assign components to a nozzle or to be able to estimate the wear of the corresponding nozzle. In order to determine the unique nozzle installed, a method is to be developed with which such interventions can be recorded in digital systems and implemented as an example for the FFF process.\n