> how we might go about fixing a massively complicated system like the NHS
You wont find a book to help with that because the real answers are not politically correct. Also because no one is willing to confront reality. It is inherently, politically unsolvable. You could sidestep reality and look for a solution that doesn't hurt peoples feelings, but the NHS is a cult as much as it is a healthcare provider.
What you are asking is, "How could we go to this Catholic Church and solve their Jesus problem". You can't do it without a paradigm altering schism.
I'd love to have a real discussion about this but no one is willing to emote even what the problems they perceive are and the bias they apply to define the root of said problems.
Thinking in Systems by Donella Meadows is great
Feedback Control for Computer Systems: Introducing Control Theory to Enterprise Programmers
May be something you want.
Drift Into Failure is a good read about how systems fail, albeit a little light on solutions.
I enjoyed Thinking in Systems: A Primer by Donella Meadows
Nancy Leveson's _Engineering a Safer World_ (available for free here: https://direct.mit.edu/books/book/2908/Engineering-a-Safer-W...) is required reading, in my opinion. It talks about applying systems theory to reducing industrial accidents, using various case studies such as the Bhopal gas tragedy, which maps automatically to reducing outage severity and incident severity for tech workers.
The key insight it applies is that root-cause analysis to fix and improve situations is limited because choice of root-cause is somewhat arbitrary - it really depends on where you stop probing further. Engineers should not rely on root-cause analysis to identify failures in _the system_, only on failures of components. Nancy proposes alternative techniques instead to identify and improve broken systems.
The detail, quality and depth of her treatment makes it immediately practical and useful. My one complaint is that it is a bit long, and not all of it is easily condensed into short treatments - but I guess verbosity is the tradeoff for quality?