From Rules To Rule Patterns

Rule-based systems are a commonly accepted solution for smoothly capturing the context-dependent and time-dependent organizational knowledge of large enterprises, also known as business policies. At the same time, however, the design of rule-based applications is one of the most pressing open research problems. This is largely because of the expressive power and flexibility of existing rule-based models together with a lack of design guidelines on how to apply these models. Learning from analogous problems in object-oriented system development and borrowing their solution metaphor we introduce rule patterns as generic rule-based solutions for specifying business policies. The advantage of rule patterns is their predefined, reusable, and dynamically customizable nature allowing the designer to reuse existing experience for building new rule-based applications. The paper introduces the general notion of rule patterns and illustrates the approach by sample rule patterns for specifying interaction policies in workflow applications.