4.2.1 INTRODUCTION

There are two distinct issues in the development, maintenance, and operation of the Plastic Injection Molding Expert System (PIMES): that of object classification and definition, and that of knowledge processing.

Object definition involves predefining classes, objects, their properties, and sometimes their values. This is a static definition of the PIMES environment, set even before action occurs.

Knowledge processing is the dynamic aspect of PIMES and centers around its rules. During knowledge processing, objects are created, modified, attached to one another, and analyzed. Data is brought in from outside databases, enhanced, and written out.

4.2.2 discusses the PIMES program with respect to Frame Definition. A frame is essentially the structuring of the data in terms of classes, objects, and their properties. 4.2.3 details the knowledge processing of PIMES, particularly with reference to feature evaluation. Although other aspects of PIMES include mold dimensioning and machine selection, they are not discussed here.