Abstract In this paper, we propose a new methodology and test system to enable the early detection and precise localization of Time-Dependent-Dielectric-Breakdown (TDDB) occurrence in Back-End-of-Line (BEOL) interconnection. The methodology is implemented as a novel Integrated Reliability Test System (IRTS). In particular, through our methodology and test system, we can easily synchronize electrical measurements and emission microscopy images to gather more accurate information and thereby gain insight into the nature of the defects and their relationship to chip manufacturing steps and materials, so that we can ultimately better engineer these steps for higher reliable systems. The details of our IRTS will be presented along with a case study and preliminary analysis results.