This paper reports on the designing of a software system for computer-aided sheet metal manufacturing. The developed system is designed to be used with a small (128 kilo-bites) computer, and it aims at realizing highly-automated punching-press and shearing processes in sheet metal manufacturing. The system consists of five processors, each of which possesses the following functions : translating input data language and producing standardized data files for subsequent processors, nesting products onto raw sheet metal blanks, determining the shear-scheduling of the products to be cut rom the raw sheet metal blanks, sorting out punching-press geometries to assign each ones to a proper task group, and determining a punchingpress tool path. The language designed for the system has information on the raw sheet metal blanks, products, and punching-press tasks. In the shearing process, it is extremely difficult to automate product allocation onto the raw sheet metal blanks. In order to solve this difficulty, a method developed for the trim problem is adopted for this system. Decision making in shear scheduling, tool path generation for punching-press, and punchingpress geometry sorting are mathematically modeled, and methods are developed to solve these models. The developed software system may raise an important role in realizing an integrated sheet metal manufacturing system.