RATIONALE

"McDermott, R1/XCON"

J. McDermott, R1: A Rule-based Configurer of Computer Systems,
Artificial Intelligence, Vol. 19, North-Holland, 1982, pp. 39-88 


XCON is a system that configures computers.  It was probably the first
system claimed to be exclusively for the Configuration task.  It is
actually doing Configuration Design, and not pure Configuration.  It
divides the problem into ordered subtasks.  XCON was one of the
largest rule-based systems ever constructed, and is notable for
actually being used in industry for many years.  Due to its size and
the dynamic nature of the knowledge being expressed in rule form it
helped to point out problems with the use of rules.