Decision Support with Fuzzy Production Systems

A production system is primarily a formalism for representing knowledge about any particular area of problem solving (Farley, 1980). A program written as a production system is a collection of “production rules,” which take the form “if left-hand-side proposition is true, then right-hand-side proposition is true.” Such a program may operate in one or both of two modes. In the “left-hand-side driven” or “modus ponens” mode, a rule compares the database with the left-hand-side proposition; if the comparison succeeds, action is taken in the database and/or the environment to make the right-hand-side proposition true. In the “right-hand-side driven,” “goal driven,” or “modus tollens” mode, the program attempts to find or create circumstances which satisfy the left-hand-side of some rule whose right-hand-side moves the system closer to its goal.