Life testing is a fundamental procedure to know the reliability of the devices, to ensure their operation in all conditions. At Kompetenzzentrum Automobil- und Industrie-Elektronik (KAI), a new test system is under development, which is described by a test-plan created and verified by a visual software. Each test-plan is composed by finite-state machines (FSMs), which allow a modular composition and extension of a test sequence. The states of a FSM contain Lua code, a script language used for executing test routines. Over the time, it became necessary to adapt the tool to build test-plans to new technologies, make it more performing and improve it to be used in a more complex context.