Classic introduction to systems analysis which is uncannily prescient given that it's almost 30 years old. I was surprised how much of my formal education and experience fits within this framework without it being explicitly referenced: analog electronics, computer systems and networks, my layman's understanding of economics. The section on feedback loops and how dynamic behavior can be created from relatively simple models particularly stuck out. I suspect this will be a book I return to regularly and I'm a little frustrated I didn't get round to it sooner.