Requirement Analysis for the Definition of Reusable Spatial Objects

Abstract

Requirement analysis plays a critical role in designing geographical information systems because it aims to capture user informational needs correctly and fully. Proposed analysis and design methodologies either adapt general-purpose approaches to this application field or extend them by introducing specific constructs to better capture the spatial properties of objects. Many of them are based on the object-oriented paradigm; unfortunately, they usually lack expressive power so that a wide gap remains between the contents of the resulting documentation and the required depth of the detailed application design. The solution we propose is based on the GeoMDT model, which combines the modeling capability of current conceptual data models with that of predicate calculus formulas under a unified paradigm in order to express object dynamics in form of invariant. The strong points of the GeoMDT model are independence of the GIS technology, easy identification of routine functions, effective guide to modular design, and a high reuse potential obtained through the nested encapsulation mechanism.