A problem-oriented approach to description and analysis of geographic requirements

Software requirements describe a problem in the real world that a software system is intended to solve. Describing requirements is challenging because usually too much attention is given to the final software product instead of concentrating on the problem itself and the real world. The area of geographic applications is no exception.; A geographic application is a computer-based system that solves a geographic problem from the natural or man-made environment using a map. Geographic applications are usually complex and data-intensive. The real world has many details that may need to be captured. A map that acts as a model of the real world reflects this complexity and has many of its own intricacies, such as a projection, a datum, and a coordinate system. The problem that an application is intended to solve is often overlooked because of the difficulties in dealing with the data.; Existing approaches to software development that are specific to the geographic area, for example, GIS tools, spatial databases, geographic query languages, and spatial data structures, are suitable for designing and implementing geographic applications and are, therefore, solution oriented. There appears to be no problem-oriented approach for requirements description of geographic applications. In addition, an informal requirements description relies on intuitive notions and ideas about geographic phenomena. This description is often imprecise. Formalizing the requirements description allows checking that the formal description has the expected characteristics of the informal notion of the geographic phenomena.; Most geographic applications are composed of well-known geographic subproblems. The proposed approach provides classes of common geographic subproblems that can be used to promote analysis and description of real-world problems. Each class of problems is presented as a problem frame. Problem frames are an existing technique in which each frame conveys the essence of a family of problems. To describe a complex problem, the analyst must recognize which parts of the problem can be framed into the given subproblems.; The proposed approach provides also a formalization of the geographic problem frames that can be used to describe the requirements of specific applications. The resulting formal descriptions can be verified against desired formal properties. The contributions of this dissertation include: an approach to informal problem description and analysis of geographic requirements, consisting of definitions of typical classes of common geographic problems and a detailed description of each geographic problem using problem frames; an approach to formal description and analysis of geographic requirements, consisting of formal descriptions of the geographic frames and of specialized requirements and specifications, as well as formal map domain descriptions; and a demonstration of informal and formal problem description and analysis using two case studies.