Think of systems thinking as an alternative to the analytic approach (break the problem apart and solve the pieces) for scenarios where that doesn't work - DM's

Think of systems thinking as an alternative to the analytic approach (break the problem apart and solve the pieces) for scenarios where that doesn't work - DM's book is meant to teach the basics of that approach. It's not designed to give you all the tools needed to solve these problems - for that, you'll need to pick up a couple of books on nonlinear dynamics if you're wanting formal modelling, or just wade in and try to think in systems terms if you're working in a more intuitive environment.