Many of the semiconductor technologies are already facing limitations while new-generation data and telecommunication systems are implemented. Although in its infancy, superconductor electronics (SCE) is capable of handling some of these high-end tasks. We have started a defect-oriented test methodology for SCE, so that reliable systems can be implemented in this technology. In this paper, the details of the study on the Rapid Single-Flux Quantum (RSFQ) process are presented. We present common defects in the SCE processes and corresponding test methodologies to detect them. The (measurement) results prove that we are able to detect possible random defects for statistical purposes in yield analysis. This paper also presents possible test methodologies for RSFQ circuits based on defect oriented testing (DOT).