This paper introduces a Computer-Aided-Test platform that has been developed for the evaluation of test techniques for analogue and mixed-signal circuits. The CAT platform, integrated in the Cadence Design Framework Environment, includes tools for fault simulation, test generation and test optimization for these types of circuits. Fault modeling and fault injection are simulator independent, which makes this approach flexible with respect to past approaches. In this paper, the use of this platform is illustrated for test optimization for the case of a fully differential amplifier. Test limits are set using a statistical circuit performance analysis that accounts for process deviations, as a trade-off between estimated test metrics at the design stage. Specification-based tests are next optimized in terms of their capability of detecting catastrophic and parametric faults.