There's a lot of things changed since the era of 'engineering judgement'. In the 50s and 60s when 'engineering judgement' was common, it was a signal to a skil

There's a lot of things changed since the era of 'engineering judgement'. In the 50s and 60s when 'engineering judgement' was common, it was a signal to a skilled machinist that "You have more experience with the material, so use your best guess because I don't know what the right answer is". Things have changed a lot! 1. Material quality is much higher. Which is to say that batch-to-batch variance is vastly reduced. This means that it's worth investing the effort in detailed understanding of the material because that material is more predictable. Which led to ... 2. We understand a _LOT_ more about material science. Our knowledge of materials is vastly higher, so things that used to be 'best guess' are now 'do this because it will reliably work'. e.g. Spallation and galling used to be poorly understood issues that were worked around based on personal experience and guesswork. Now we understand them very well, and any competent manufacturer will clearly explain exactly how to (eg) install their bearing in a way that prevents such issues. 3. Expertise shifted. The 'machinist' is no longer a 20-year experienced highly trained person, but a CNC operator, who probably won't be within eye-sight of the running machine. So the practice of 'increase the RPM until it chatters slightly then back off' doesn't cut it any more. The answer needs to be known up-front to go into the G-code, not 'feel'. This has led to the obvious cycle where more responsibility moved to the engineering end, which increased the demand for exact knowledge, which reduced the requirements on machinists, which led to lower skill, which further moved responsibility to engineering. So I totally get pining for the era of 'engineering judgement', but it died for a reason and it's not really likely to come back!