A NEW INTEGRATED SOFTWARE-DEVELOPMENT ENVIRONMENT BASED ON SDL, MSG, AND CHILL FOR LARGE-SCALE SWITCHING SYSTEMS

This paper presents a new software development environment that suppor ts an integrated methodology for covering all phases of software devel opment and gives integrated methods with tools for ITU-T (Telecommunic ation Standardization Section of the International Telecommunication U nion) languages. The design of the environment to improve software pro ductivity and quality is based on five main concepts: 1) formal specif ications based on SDL (Specification and Description Language) and MSC (Message Sequence Charts) in the design phase, 2) verification and va lidation of those designs by tools, 3) automatic code generation and a safe separate compilation scheme based on CHILL (CCITT High-Level Lan guage) to facilitate programming-in-the-many and programming-in-the-la rge. 4) debugging of distributed real-time concurrent CHILL programs, and 5) simulation of application software for integrated testing on th e host machine based on CHILL. The application results of the environm ent compared with other approaches show that the productivity is incre ased by 19 % because of decreasing implementation and testing cost, an d the quality is increased by 83 % because of the formal specification s with its static and dynamic checking facilities.