Reducing matching time for OPS5 production systems

A rule-based system must satisfy stringent timing constraints when applied to a real-time environment. The most critical performance factor in the implementation of a production system is the condition-testing algorithm. We show an approach designed to reduce the response time of rule-based expert systems by reducing the matching time based on RETE. There are two steps in the method we propose: the first makes an index structure of the tokens to reduce the α-node-level join candidates; the second chooses the highest time tag for certain β-nodes to reduce the size of the β-memory and to keep the strategy of the RETE network. These steps reduce the amount of combinatorial match that is problematical in a real-time production system application