Network Design and Analysis. Network development and design tool for the design, analysis, and optimization of SNA subarea, SNA APPN, APPN HPR, and NCP frame relay networks. A z/VM version was withdrawn December 1988, but the z/OS version is still available, though the last release, Version 2.2, was first announced February 1991. Both require GDDM. See also NetDA/2 for the OS/2 version.