A multi-agent system can be analyzed and specified as an organization consisting of roles and their relations. The performance of an organization depends on many factors among which the topology of its organizational structure, i.e., the set of relations holding between its roles. This short paper provides the sketch of quantitative methods for addressing the issue of the analysis, evaluation, and comparison of organizational structures. To this aim, quantitative concepts from graph theory are applied which deliver numerical analyzes of organizational structures. Here, an illustrative number of these concepts is sketched and their connection to properties that are commonly indicated as critical for organizations (robustness, flexibility and efficiency) is shown. Categories and Subject Descriptors F.2.11 [Distributed Artificial Intelligence]: Multiagent Systems-Multiagent Organizations; F.2.11 [Distributed Artificial Intelligence]: Coherence and Coordination General Terms Theory. Keywo...