Disclosed are methods for improving integrated circuit (IC) chip reliability. IC chips are manufactured and sorted into groups corresponding to process windows within a process distribution for the design. Group fail rates are set for each group based on failure mechanism fail rates, which are set for multiple failure mechanisms. An overall fail rate is determined for the full process distribution based on the group fail rates. First contribution amounts of the groups to the overall fail rate and second contribution amounts of the failure mechanisms to the group fail rate of each group are determined. Based on an analysis of the contribution amounts, at least one specific failure mechanism is selected and targeted for improvement (i.e., changes directed to the specific failure mechanism(s) are proposed and implemented). Optionally, proposed change(s) are only implemented if they will be sufficient to meet a reliability requirement and/or will not be cost-prohibitive.