A patent portfolio is more valuable than a single patent. However, the analysis approach of a company's patent portfolio is still ambiguous. The patent priority approach (PPA) presented a clearer analysis method to explore the interior of a patent family; patent families provide an outline of the patent portfolio. A patent priority analysis (PPA) could give a better picture of the patent portfolio path, and provide technical tracks through the patent family priorities. This paper evaluates the patent family priority network (PFPN), by joining whole patent family members to PPA. The length and quantity of the patent chain represent the depth and width of the technical developments. Special nodes are also found. When the PFPN has any "merge patents", the GR of the patent chain would fail to choose the right critical chain. A burst patent node bursts one path into several paths. SSR fails to choose the correct significant chain with burst patent nodes. Although the number of priority patents claimed by each family member (GR) and the cumulative sum of the priority patents for the patent family member (SSR) fail in the special situations, PFPN still could provide a simple, precise and broadly useful approach for technical development.