rs use models or abstractions that hide low-level implementation details. Various kinds of representations such as data models, state-transition models, and dataflow models can help designers understand and implement these software systems. Our line of work--building database applications--focuses on data structure models that facilitate storing and retrieving data. In doing so, we lly search for abstractions that enhance our understanding of these structures as well as our ability to subsequently manipulate data in the actual database application. One such pattern we have repeatedly found useful nominally expresses softcoded values as a data model, but also involves object-oriented concepts and application-specific constraints and behavior. An equipment example describes an application of this pattern in industry. We use the popular Unified Modeling Language (UML) notation,1,2 a comprehensive suite of object-oriented models intended to represent software applications fully, to illustr...
Michael R. Blaha, Cheryl Smith