Method for monitoring the operation of a technical object (TO) with the aid of a mathematical model (MLM) based on machine learning after assembly of a three-axle replacement acceleration sensor (ES), wherein a three-axle first acceleration sensor (S1) is initially assembled on the object (TO) at a position, and during operation the object (TO) generates mechanical oscillations, and the following steps are carried out: a) Determining a first orientation (OS1) of the first acceleration sensor on the object (TO) in the form of a position vector (LV) relative to the gravitational force, b) Generating and training the mathematical model (MLM) for monitoring the object (TO) with respect to the position vector (LV), c) Disassembly of the first acceleration sensor (S1) and assembly of the three-axle replacement acceleration sensor (ES) with a new orientation (OES) on the object (TO) at the same position, at which the first acceleration sensor (S1) was assembled, characterised by the following additional steps: d) Detecting acceleration values (A) in the x-, y- and z-direction with the aid of respective individual sensors of the three-axle replacement acceleration sensor (ES) of the object (TO), e) Calculating respective indicator values from the temporal course of the detected acceleration values (A) of the replacement acceleration sensor (ES) f) Determining a replacement vector from the indicator values and determining a differential vector (DV) between the replacement vector and the position vector (LV) of the first acceleration sensor (S1) determined in step b), g) Monitoring the operation of the object by applying the model (MLM) during operation (BTO) of the object (TO) for the position vector (LV) in the orientation of the replacement vector by taking into account the differential vector (DV). a) Determining a first orientation (OS1) of the first acceleration sensor on the object (TO) in the form of a position vector (LV) relative to the gravitational force, b) Generating and training the mathematical model (MLM) for monitoring the object (TO) with respect to the position vector (LV), c) Disassembly of the first acceleration sensor (S1) and assembly of the three-axle replacement acceleration sensor (ES) with a new orientation (OES) on the object (TO) at the same position, at which the first acceleration sensor (S1) was assembled, characterised by the following additional steps: d) Detecting acceleration values (A) in the x-, y- and z-direction with the aid of respective individual sensors of the three-axle replacement acceleration sensor (ES) of the object (TO), e) Calculating respective indicator values from the temporal course of the detected acceleration values (A) of the replacement acceleration sensor (ES) f) Determining a replacement vector from the indicator values and determining a differential vector (DV) between the replacement vector and the position vector (LV) of the first acceleration sensor (S1) determined in step b), g) Monitoring the operation of the object by applying the model (MLM) during operation (BTO) of the object (TO) for the position vector (LV) in the orientation of the replacement vector by taking into account the differential vector (DV). <EOS>