The productivity of developing software for switching systems and the effects of using advanced software development methods were evaluated and analyzed. Productivity was found to be improved by using automatic code generation, simulator debugging, a hierarchical object-oriented software structure, and software-development-support tools. The evaluation showed that the total productivity was improved by about 20%, compared with a case where these efforts were not introduced. It also showed each effect of these methods and tools by evaluating their manpower saving ratios. These results are expected to benefit the development of various types of communication-switching and multimedia service systems. Also, our development-support tools and methods are expected to be the basis for attaining higher software development productivity.

This paper describes key techniques for automatic program generation of office data handling for all types of switching systems. Our office data scenario tool generates logical-physical office data conversion programs to be installed in switching systems. Also, it generates logical office data generation programs to be installed in a logical office data generation tool that converts office conditions to a logical office data file. We were able to apply this tool to all the office data types for our new switching systems, and automatically generated about 5. 5% of the total program size. This technique reduces not only the software production cost but also the bug ratio because there is no room for human error. Also, switching system programs are much more portable, since no machine-code-dependent parts are involved in office data handling. Thus, we expect that these techniques will be the basis for highly productive, reliable, and portable software platforms for the next-generation multimedia communication systems.

Key technologies are presented for enhancing the reusability of software in communication switching node systems along with the results obtained from porting software between several types of node systems, including N-ISDN, B-ISDNs, and Intelligent Networks. A reusable software platform based on object-oriented designing and programming techniques has been established and mechanisms for reusing object classes has been developed. Analysis of the reusability showed that this platform can be applied to various types of communication systems and that an average of more than three quarters of a system's programs can be ported. By using our software reuse framework to develop software components, we were able to reduce the time needed to develop device management programs by about 30%. Furthermore, about 80% of these programs can be ported to other systems, so introducing this platform improves software programming productivity.