A hardware electrical design for reliability process is presented that uses extensive modeling and simulation to provide key information for design, component engineering, and reliability engineering to build robust designs that demonstrate design margin, identify critical features for operations (e.g. supply chain and final test), and enable predictive reliability. The methodology integrates reliability analysis into the hardware development process, thus improving design decisions and ensuring product reliability early in the life cycle. To demonstrate the methodology, simulation environment and model infrastructure of an ICD charge and delivery circuit have been accomplished, with methods of estimating component and subsequent circuit reliability presented. Furthermore, variability-based simulations were demonstrated to understand circuit performance limits and to properly define component selection and control strategies.