Every organization has at least one requirement that has been discussed more times than it has been implemented. It has a document. The document has version history. The version history has moods. Reasonable, well-paid adults have gathered around this requirement on four separate occasions, produced diagrams of increasing beauty, and left the room with less clarity than they arrived with, which is an impressive trick when you consider that they were all trying to help. The usual explanation is that the requirement is unclear. It isn't. The usual remedy is more precision. It won't work. You can define the term...