GPS ground antenna and monitor station upgrades: software requirements analysis

This paper discusses the software aspects of the Global Positioning System (GPS) remote site modernization study, specifically, the software requirements analysis. At the beginning of the software requirements analysis phase, a qualitative trade-off study was performed to determine if a structured analysis or an object-oriented analysis (OOA) approach would be followed. The latter was chosen because it offers a number of advantages over the life-cycle of a software development project. This paper outlines these advantages. In conjunction with this methodology study, a study of Computer-aided Software Engineering (CASE) tools was performed to ascertain if available software requirements analysis and design tools would aid the software development process, in general, and requirements analysis, in particular. The results of this study are also summarized in this paper. The paper also discusses the experiences of Draper Laboratory software engineers in using OOA to perform software requirements analysis for a large software project (over 100,000 lines of Ada source code estimated), and how this approach was followed while specifying requirements using the Software Requirements Specification Data Item Description (DID) that accompanies DOD-STD-2167A.