System and method for detecting hardware degradation in a radiation therapy system arranged for delivering a plurality of fractions for a plurality of radiation fields. The system includes a measurement unit arranged for measuring, for each fraction of the plurality of radiation fields, a value for one or more quantities representative of a functioning of one or more hardware components of the system. The system includes a normalizer arranged for, for each of the one or more quantities, normalizing the measured values. The system includes an averaging unit arranged for, for each of the one or more quantities, determining an average of the normalized values. The system includes a comparator arranged for, for each of the one or more quantities, comparing the average of the normalized values with a respective predetermined value.
