MAINTAINING PROCEDURAL KNOWLEDGE: RIPPLE-DOWN-FUNCTIONS

Research into the maintenance of procedural knowledge has focused on the detection of declarative meta-structures within the procedures. An alternative approach is described here based on the ripple-down-rules (RDR) formalism. To the standard RDR rule tree, we add a functions environment hierarchy that stores the implementation of the procedures used in the rules. This functions environment structures the evolution of functions and scopes the effect of a newer version of a procedure to the rules that require it. We describe implementation techniques for the maintenance environment using commerciallyavailable tools.