An expert system for softwood lumber grading

To accommodate future applications of scanning technology and minimize differences in the interpretation of written rules, a prototype expert system for grading green softwood lumber was developed. It was also intended to be part of the expansion of a log breakdown model to include internal defect information in the optimization process. The systemʹs knowledge base consists of pertinent green grading rules based on the Western Wood Products Associationʹs (1988) “Western Lumber Grading Rules 88” for 27 grades in the dimension, selects and finish, and board categories. The system is designed to be either interactive and menu-driven or run in a batch input mode. User input to the system consists of lumber size; desired primary grade category; and defect information such as type, location, and size on each face and edge. The system then infers the grade corresponding to each side and an overall grade for the board. Limited explanation capabilities are provided.