> trying to control those engineering processes with SPC doesn't really improve the quality of the engineering, it just adds stress, makes things take longer, and probably lowers the quality of the thing that is being engineered
Totally depends on the scale. For pizza-sized times with a neighbourhood pizza shop sized impact, sure. Large scale projects without controls & feedback loops in place will fall apart; see: Scaling teams: https://archive.is/FQKJH
If you'd follow some medium to large scale projects (like Go / Chromium), the value of processes & quality control, even if it may seem at the expense of velocity, becomes clear.
The great insight of Deming's methods is that you can (mostly) identify the difference between common and special causes mathematically, and that you should not attempt to fix common causes directly - it's a waste of time, because all real-life processes have random variation.
Instead, what you want to do is identify your mean and standard deviation, plot the distribution, and try to clean it up. Rather than poking around at the weird edges of the distribution, can we adjust the mean left or right to get more output closer to what we want? Can we reduce the overall standard deviation - not any one outlier - by changing something fundamental about the process?
As part of that, you might find out that your process is actually not in control at all, and most of your problems are "special" causes. This means you're overdriving your process. For example, software developers working super long hours to meet a deadline might produce bursts of high producitivity followed by indeterminate periods of collapse (or they quit and the whole thing shuts down, or whatever). Running them at a reasonable rate might give worse short-term results, but more predictable results over time, and predictable results are where quality comes from.
Totally depends on the scale. For pizza-sized times with a neighbourhood pizza shop sized impact, sure. Large scale projects without controls & feedback loops in place will fall apart; see: Scaling teams: https://archive.is/FQKJH
If you'd follow some medium to large scale projects (like Go / Chromium), the value of processes & quality control, even if it may seem at the expense of velocity, becomes clear.
https://apenwarr.ca/log/20161226Distributed systems is also a way to be throughly humbled by complexity: https://fly.io/blog/corrosion/