The basic question that first needs to be asked at Qantas is “Are we seeing a trend here?”. Fortunately there is a definitive way of answering this question that is not subject to bar or Board room debate; that method is statistical process control. I would be very surprised if QF was not recording the number of occurrences (doesn’t matter how severe or not) by fleet, as well as probably by ATA Chapter and possibly even finer classifications. For each classification one calculates say monthlly averages as well as standard deviation using the normal distribution.
By definition, plus or minus three standard deviations covers 99.95% of averages. If the number of occurrences falls outside average plus 3 X standard devs, then you can be 99.95% sure that “something” has happened to your performance. Inside three standard deviations you can consign the peaks and troughs to “noise”.
Once you have determined that “something” has happened to your performance, then of course it is then, and only then, that you can start debating and investigativng what it is that has changed. Until you have done this statistical test, you are just speculating.
I would be very surprised if Qantas did NOT have a very. sophisticated system that tracks and evaluates occurrences this way right across each fleet. I would also expect that a summary of the monthly output from such monitoring systems was not routinely shared with CASA and ATSB, as the stuff I generated for Ansett was in the 1970’s.
‘’If QF, ATSB or CASA do not already have this data and associated tools and already know the answer about. these occurrences then God help us.
https://asq.org/quality-resources/st...rocess-control
* The website is wrong about the history of SPC, it goes back to the first world war and torpedo production problems.