Many metrics such as degree, closeness, and PageRank have been introduced to determine the relative importance of a node within a network. The desired function of a network, however, is domain-specific. For example, the robustness can be crucial for a communication network, while efficiency is more preferred for fast spreading of advertisements in viral marketing. The information provided by some widely used measures are often conflicting under such varying demands. In this paper, we present a novel framework for evaluating network metrics regarding typical functional requirements. We also propose an analysis of five well established measures to compare their performance of ranking nodes on functional importance in a real-life network.