Thesis (Ph.D.)--Chulalongkorn University, 2002

An alternative scheme to formal software specification is explicitly proposed. In our approach, a formal software specification is formally defined as a set of decision rules performed by a software system. We propose a set of graphical notations called Requirements Particle Network (RPN), to describe the essential preconditions and operations needed by a software system according to the decision rules. A RPN consists of a set of particles and edges to construct a visual model of a decision rule during the software analysis phase. In addition, a number of transformation rules are proposed to perform the formal specification synthesis. A set of predefined formal requirements particle definitions is written in prior and reused during the transformation steps. A developer is provided a practical mean to write a formal specification with a brief experience in mathematical background. In this research, we demonstrate the Z formal specification synthesis using RPN. The usability of the RPN approach is investigated by conducting a workshop. The result indicates that a developer with experience in writing data flow diagram is capable to produce a complete and consistent RPN. Moreover, we show a case study of applying RPN to construct a composite operation to be used in database applications