Slicing is a process for automatically obtaining subparts of a program with a collective meaning. It has been employed within conventional procedural programming to solve a number of software development issues. We have adapted and extended slicing techniques originally proposed for procedural languages, to knowledge-based systems. Our techniques comprise a representation proposal for the successful and failed inferences performed by the system, a means to detect and represent the dependences among parts of the system, a formal definition of relevance among these parts and an algorithm proven correct to obtain executable slices of a system. We illustrate the usefulness of the slicing process with practical examples. Keywords. Slicing techniques, automated support, development and reuse of systems. 1 Introduction Knowledge-based systems (KBS's), as any other piece of software, are prone to the usual difficulties of program development, maintenance and reuse. Program slicing, a ...