Structural design optimization has become an effective paradigm for designing and developing various kinds of products. However, it is not so popular in the electric appliances in spite of their small sizes and relatively simple configurations. It is very important to identify design specification and to organize appropriate design process in the field of electric appliances. The authors have proposed the strategic scheme for systematically identifying specifications for structural design optimization. In this paper, we studied the structural design optimization for a propeller fan which used laser welding as example to apply the proposed methodology. As a result, it was obtained a new structure of propeller fan achieving high reliability and low cost.