A method of monitoring the quality of an audio video process chain includes taking a plurality of measurements M, each measurement being converted into a threshold confidence TC by a normalisation process, where required. Each resultant threshold confidence is compared with a threshold value of acceptability in which the comparison takes into account a latitude of acceptability associated with that threshold and an error function relating to the reliability of the measurement. The threshold confidence indicates a level of pass or fail and extends linearly between a value indicative of full acceptability/pass (e.g. 100%) and a value indicating certain unacceptability/fail (e.g. 0%) (see e.g. figure 2a). By normalizing a plurality of measurements at different stages of the process chain, different measurements may be assessed and compared on the same threshold confidence scale. Also disclosed is a method of monitoring the quality of an audio video process chain comprising taking a plurality of measurements, generating an error function for each measurement, and combining each measurement with its respective error function to form a measurement range. A user is provided with an option, available via a graphical user interface (GUI), to manually override a determined threshold confidence if the result of the automated monitoring is determined to be erroneous.