This paper addresses the design of system-based component test plans for demonstrating reliability of a series system. There are two primary contributions of this work. First, unlike most of the prior work in this area which has relied on the component failure times being exponentially distributed, this paper examines another common failure time distribution, namely the Weibull distribution and develops a test plan that exploits the relationship between the Weibull and the exponential distributions. Second, it introduces the notion of imperfect interfaces between components within the system which is another issue that all prior work has ignored, and results in plans that also call for system level tests.