How to Print a File: An Expert System Approach to Software Knowledge Representation

Abstract

Representing knowledge of software and software systems is an important research area and a prerequisite to engineering expert-level systems to do software tasks. Printing a file in a UNIX™ environment is an example of a real-world problem that can pose surprising difficulties to UNIX users. The printing of files is also illustrative of a class of software problems characterized by the recombination of existing programs. Automating the printing process involves designing knowledge representations to appropriately capture knowledge of both the printing software and the printing process and designing a reasoning system that uses those knowledge representations in a working implementation. This paper examines the printing problem in detail, presents a model of printing and printing software, and describes an implementation designed to test the model and identify the next set of research issues. The implementation, ESP, for Expert System for Software, successfully automates the printing process and illustrates a knowledge-based approach to software problems.