OBIRCH (Optical Beam Induced Resistivity Change) has been developed to an industrial useable equipment for failure localization. The method turned out to be in certain manner complementary to emission microscopy, detecting failures mainly related to metal wiring problems. At EMPA, EM Microelectronic Marin and CNES Toulouse, first experiences have been collected with this method, using external and CNES-owned OBIRCH equipment. It turned out, that the method does not only help to localize functional failures, but is also most suitable as a reliability-related failure detection tool: OBIRCH-indicates signals at positions where no electrical failure could be seen in standard electrical testing. Analyzing those positions physically, it turned out that indeed significant failure textures have been found, which, however, did not show up electrically, yet. On the other hand, application of OBIRCH on functional devices shows some severe limitations. Thus, OBIRCH might become an interesting in-line tool of the future to detect and to screen reliability-critical failure types, which would pass all present electrical in-line testing on PCMs (Process Control Monitor structures).