Lots of insights on lean engineering in this interview to Elon Musk:
https://www.youtube.com/watch?v=t705r8ICkRw

#spacex #starship

At 13:13 into the video, he mumbles:

"W-what I'm trying... I have a solve this... err... implement rigorously is this sort of 5 step process:

1. Your requirements are definitely dumb: everyone's wrong, no matter who they are [...] So try to make your requirements less dumb."

#spacex #starship

2. Then, try to delete the part or process.

The bias tends to be very strongly in favor of adding parts in case we need them... but you can basically make "in case" arguments for so many things! [...]

So, you gotta delete the parts or process steps that you don't need.

#spacex #starship

3. Whatever requirement or constraint you have, it must come with a name, not a department. Because you can't ask the departments, you have to ask a person

[...] otherwise you could have a requirement that basically an intern 2 years ago randomly came up with off the cuff... and they're not even at the company any more... but it came from the, let's say, Air Flow Department!

#spacex #starship

4 Only the third step is to simplify or optimize [he seems to be off-by-1].

Possibly the most common error of a smart engineer is to optimize the thing that should not exist. Everyone has been trained in school that you gotta answer the question -
convergent logic. So you can't tell a professor "your question is dumb" - you'll get a bad grade!

So everyone basically - without knowing it - they got a mental straight-jacket on: they'll work on optimizing the thing that should simply not exist!