The purpose of this paper is to present the Integrated Design System (IDS) using both the Failure Mode and Effect Analysis (FMEA) and the Axiomatic Design. The IDS can be reduced by both the design complexity of the functional dependence mapping from axiomatic design and the potentail failure from the functional work breakdown structure of the FMEA. The IDS consists of the following three stages: i)Determination of simplified design mapping path by using functional independence of Functional Requirements(FRs) and Design Parameters(DPs) ii)Calculation of Risk Priority Numbers(RPNs) for hierarchical breakdown systems in response to the Cause-Mode-Effect casual relationship based on the functional independence mapping iii)Reliability improvement by redesigning the DPs of the Critical Design Tree(CDT) exceeding the desired individual RPNs threshold. For a better understanding of the proposed integrated design system of FMEA and axiomatic design, case studies with decoupled design and uncoupled design are presented in this paper.