Organizations require security systems that are flexible and adaptable in order to combat increasing threats from software vulnerabilities, virus attacks and other malicious code, in addition to internal attacks. Network intrusion detection systems, which are part of the layered defense scheme, must be able to meet these organizational objectives in order to be effective. Although signature based network intrusion detection systems meet several organizational security objectives, heuristic based network intrusion detection systems are able to fully meet the objectives of the organization. Through a comparative theoretical study, this paper analyzes several organizational security objectives in order to determine the network intrusion detection system that effectively meets these objectives. Through conclusive analysis of the study, heuristic based systems are better served to meet the organizational objectives than signature based systems. The analysis was based on which system provided definitive security objectives and offered the flexibility, adaptability, and reduced vulnerability that an organization requires.