"With spacecraft no chance of changing parts when you're near Mercury or Mars." Pre-planning essential.
Human brain is most complex system. "Best advice, use your brain. More complex than a computer."
Need to simplify systems. A system is a connection of different elements. If no way to calcualte future state of system, then you have complex system. Use other instruments.
Process approach: dynamic network of processes and interactions. Most things in life not predictable. When analysing system need to get creative.