抄録
In software development, if we regard a program as a function, then specifications of this program can be seen as definitions of the relationships between the input and the output data of the program. If the input and output data structures of the program and the relationships between them are stepwise refined and defined, then it is possible to start sortware design even if the details of the requirement and of the data structures have not yet been fully determined. Furthermore, output-oriented analysis and design on stepwise refinement can reduce the need for the intermediate files that are produced during clash handling. In this paper, we will offer a specification methodology, SDR, which approach is based on the stepwise data structure refinement strategy.