Much of the governing process in the United States (U.S.) today depends on a reliable and well protected public information technology (IT) infrastructure. The Department of Homeland Security (DHS) is tasked with the responsibility of protecting the country's IT infrastructure. Critics contend that the DHS has failed to address planning and policy concerns related to the protection of this infrastructure from cyber-terrorism. The purpose of this study was to identify network vulnerabilities that may be exploited by cyber-terrorists and offer policy recommendations to alleviate this problem. This study explored factors preventing DHS from properly planning for critical network protection and investigated whether private sector models can be used to alleviate factors that inhibit network security in terms of efficiency and network performance. Bertalanffy's systems thinking model provided the theoretical foundation for this study. Additionally, Royce's waterfall model and system engineering models from production flow theory were used to supplement Bertalanffy's work and adapt it to an IT environment. The study used a mixed model research design that combined content analysis and Q methodology with descriptive statistics. The Q methodology and descriptive statistics approach included a 17 statement survey sample about IT networks. The study documented that IT professionals perceive that DHS's current approach to assessing risks to U.S. IT infrastructure and designing policies to mitigate those risks as inadequate. IT professionals prefer a more systematic approach to IT infrastructure protection planning and policy. The results of this study provide a means to impact positive social change by offering the framework for a model to perform early assessments of cyber-terrorism threats to our critical infrastructure network systems and mitigate those threats. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com/en-US/products/dissertations/individuals.shtml.]