Common cause failures (CCFs) could be a serious threat to reliability of safety-related systems used at nuclear power plants (NPPs). Modern national and international normative documents require implementation and demonstration of measures to overcome CCFs. For example, BTP 7-19 states that diversity or testability is sufficient to eliminate consideration of software based or software logic based CCF. Diversity is the general approach based on differences in equipment, development and verification technologies, implemented functions, etc. Testability could be defined as implementing software in a way that decreases effort needed to validate the system. Practical issues related to diversity and testability include implementation, assessment, and demonstration of conformance to requirements. In this paper, we share experience gained during the design of the RadICS Platform. We discuss the following defensive measures protecting against CCFs implemented in RadICS: - Software Development Process Quality; - Hardware Independence Principles; - Platform Diversity and Platform based I&C system diversity; - Defense-in-Depth. We describe assessment approach including NUREG/CR-7007 technique and tool to calculate diversity metrics and make decisions to adequacy of the diversity strategy. We present a case study for a developed and implemented NPP I&C system.