Via location and metal coverage have direct correlation. Optical proximity correction (OPC) always do selective sizing for metal to offer enough via enclosure, such as extending line end or doing external expansion for related metal edge. Hence via poor landing or metal bridging are both potential hotspots. For 14nm technology node and below, process related weak patterns are highly correlated with via locations and corresponding metal dimensions. A via optimization methodology has been put forward to enhance the robustness of design for physical design in fabless. With the aid of lithography check, the yield killers with high potential relativity with vias will be conducted root cause analysis. This paper describes the main solutions for fabless, including pin location blockage, via shift, via shape change, metal sizing change and so on within design rule check (DRC) constraints. The simulation experiment results prove the effective of these solutions due to related simulated yield killers being eliminated.