Discovering domain terminology is essential, and this terminology becomes a part of the Ubiquitous Language. However, the process of discovery can be rather lengthy and not always successful. When we discuss how the business works and what problems we are going to solve by writing software, too often the conversation comes down to discussing the features that the business is keen to implement. A set of features, of course, can be called software, but it does not necessarily form a system. Furthermore, to build a comprehensive solution for a particular problem, more system-level thinking is required.
Thinking in systems is only briefly covered in this book. To know the subject better, please refer to great books on this topic like the classic An Introduction to General System Thinking by Gerald Weinberg and Thinking in Systems by Donella H. Meadows, et al.
But who...