An excerpt from the preface of my book.
One important aspect of systems-thinking is that a system is not its components but is defined by the way these interact in a way that creates the behavior.
But the nature of these interactions are very complex – meaning that they can’t be predicted. Unforeseen events & interactions occur. And sometimes small mis-understandings cause huge side effects. This is a reflection that product development is both complex (unknowable in advance) and chaotic (small things can have big effects).
While I believe a deep understanding of complexity can be useful, very little is needed to attend to it. In the same way engineers were quite effective in building magnificent edifices (e.g., the Pyramids) without a full understanding of the science underneath them, it is possible to adjust the behavior of complex systems without understanding the exact results of proposed changes.
We mostly need is to know that 1) our changes may produce unexpected behavior and 2) we are embedded in a system where small errors can cause big changes. This requires quick feedback both about the actions we take and process improvements we try. Both agility of development and improvement of our methods is required.