For The Characteristics Method And Its Application To Expert Information System

Feature-oriented method is widely used in domain engineering. However, the vertical features have different forms and purposes in each layer of multi-layered systems, and they are implemented respectively in each layer, so that it's hard to cope with the changes of vertical requirements. To address this problem, paper proposes a new definition for "feature", that is "a feature is a requirement, which is described as a few of simple parameters". This way, the parameters of a feature can be shared by any layer of a multi-layered system.Under the instruction of feature-oriented domain analysis and modeling method, a detailed feature analysis on Expert Information System is performed, and the horizontal features (business logic or user interface) and the vertical features (business data) are extracted; at the same time, the relations between the features are confirmed. After refactoring theses features, the tightly connected ones are packed into a function-unit to ease configuration for feature composition. Meanwhile, dynamic program-generation technology, which is based on vertical features, is exploited to auto-generate user-interfaces and business logics. And a set of design patterns are adopted to support customized extensions for application development.Based on the previous work, an application framework for Expert Information System is designed and implemented. On the one hand, the framework is the infrastructure for feature composition, which is the primary instrument for application development, and most of the user interfaces and business logics are auto-generated in runtime. On the other hand, the framework is also the configuration environment for feature composition, and system functions are dynamically added, adjusted, or removed in runtime.The practice shows that the improved feature-oriented method can help increase the efficiency of system development and reduce the impact of changes of business data structure on system implementation. Further more, the method can also be used for reference in other database application development.