The CADMUS-system for computer aided design and modeling for ultrasonic applications is presented. The Windows-supported menu-system is implemented on PC-basis thus retaining user-friendliness to a high degree. At the present stage, it incorporates analytical modeling as applied for transducer optimization. As a new feature, a flaw scattering module for backwall-breaking cracks is presented. In view of verification and comparison with experimental data, a signal processing subsystem-based on a multi-processing DSP-unit-to be incorporated for detection, analysis and synthesis of ultrasonic data is also shown. The modular arrangement of the software allows for an easy up-dating with respect to customer-directed applications.