To deal with failure analysis laboratory tasks, we have developed a modular and smart test system. We demonstrate that Smart Testing Interface can keep a device in the proper electrical state for defect localization. It is a key part of our system and can be easily adapted on a wide range of electrical testers. It offers a unique combination of a slave and a standalone mode. In slave mode, it has a non-disruptive interface between the tester and the component. In stand-alone mode, it is an electrical stimuli generator that can keep the device under test in the correct internal electrical state during IC defect localization. A battery or a power supply powers it up. It can be readily carried in stand-alone mode from one tool to another tool. In stand-alone mode, it has a range of eight hours or more according to the battery capacity and device consumption. We will review a failure analysis laboratory needs and then describe test solutions with our Modular and Smart Test System and a 344 I/O Smart Testing Interface. It is used for EMMI and OBIRCH applications on PHEMOS 1000.