A technique to reuse standardized software components is presented which features a component development process and component-oriented object layers together with validity demonstrated through applications. The approach is called the 'standardized components and their composition approach.' The technique, on the condition that the architecture of a product family is fixed for a certain period of time, has the following features: (1) development of software components and that of software products are performed independently, and (2) guidelines for software component analysis/design can be obtained using an object layer which is based on shared software resources (called objects). This software component development approach has been applied to three different cases: process monitoring and control software (mainly Fortran); distributed information processing system software (Cobol); and microcomputer embedded product control software (C and assembler). Excellent results have been obtained.>

In software development, it has been pointed out that software engineers must pay attention to software requirements definition. One of the important problems in software engineering is to rationalize the processes from requirements definition to design. Computer tools are most useful and efficient for this purpose. This paper proposes a computer-aided software design system (CASDS), which supports software engineers with a series of structural modeling. As is well-known in systems planning, structural modeling helps to extract concepts from many fuzzy requirements. This system contains three structural modeling methods. They are used 1) to determine functional terms from fuzzy software requirements, 2) to obtain modules by structuring the functions with respect to the data flows, and 3) to make a program skeleton by imposing control flows on the functional elements obtained by breaking down the modules.