In product design, the initial design stage is being increasingly emphasized because it significantly influences the successive product development and production stages. However, for larger and more complex products, it is very difficult to accurately predict product reliability in the initial design stage. Various design methodologies have been proposed to resolve this issue, but maintaining reliability while exploring design alternatives is yet to be achieved. Therefore, this paper proposes a methodology for conceptual design considering reliability issues that may arise in the successive detailed design stages. The methodology integrates the independency of axiomatic design and the hierarchical structure of failure mode, effects, and criticality analysis (FMECA), which is a technique widely used to analyze product reliability. We applied the proposed methodology to a liquefied natural gas fuel gas supply system to verify its effectiveness in the reliability improvement of the design process. (C) 2017 Society of Naval Architects of Korea. Production and hosting by Elsevier B.V.