Method and apparatus for monitoring a state of a passenger transport system by using a digital double

The invention relates to a method (100) and an apparatus (1) for monitoring a state of a physical passenger transport system (2). The method (100) comprises monitoring the state of the passenger transport system (2) by using an updated digital data record double (102) that reproduces characterising properties of components of the physical passenger transport system (2) in an actual configuration of the passenger transport system in a machine-processable manner after assembly and installation thereof in a building (5). In the physical passenger transport system (2), at least one detection device (200) is arranged, which detects changes in at least one characterising property, said changes occurring as a result of wear on a circumferentially arranged, physical component (7, 11, 31, 36) of the physical passenger transport system (2). These changes are transferred to the updated digital data record double (102), wherein by means of monitoring, changes and change trends in respect of the components are tracked and assessed by means of the updated digital data record double (102) using calculations and/or static and dynamic simulations.