DDD
DDD (please note the last D is not for development, but indeed design) is a complete method for functional design that has been created and documented by Eric Evans, in his foundational book, Domain-Driven Design: Tackling Complexity in the Heart of Software, released in 2003 and, since then, has been famously known as the blue book. This important piece of work has influenced many software designers, despite it being quite a difficult read. Through its hundreds of pages, this book dispenses lots of best practices in modeling data and functional design. It is oriented towards software but everything it says can help, even before the first line of code, and it is a wealth of advice for understanding your business functions before you even start thinking about automating them through IT solutions.
That being said, our goal here is not to talk too much about the book, or to unroll the complete method. You have to read it yourself if you want to get the full advantage of such a...