Monday, March 08, 2004

Software Architecture is "Union of All Manuals". This definition fits in nicely with the (re)emergence of an architecture as a set of views, each couched in a domain specific language: In programming, the term architecture was first used to mean a description of a computer system that applied equally to more than one actual system. In 1969, Fred Brooks and Ken Iverson called architecture the "conceptual structure of a computer...as seen by the programmer". A few years later, Brooks (crediting Gerald Blaauw for the term) defined architecture as "the complete and detailed specification of the user interface. For a computer, this is the programming manual. For a compiler, it is the language manual... For the entire system it is the union of the manuals the user must consult to do his entire job." A careful distinction was drawn between architecture and implementation. Quoting Blaauw, Brooks writes, "Where architecture tells what happens, implementation tells how it is made to happen." This distinction survives today, and in the era of object-oriented programming it thrives. [emphasis added] 3:55:11 PM    comment []  trackback []