of the Keynote: Partial Behavior Modeling Although software behavior modeling and analysis has been shown to be successful in uncovering subtle requirements and design errors, adoption by practitioners has been slow. One of the reasons for this is that traditional approaches to behavior models are required to be complete descriptions of the system behavior up to some level of abstraction, i.e., the transition system is assumed to completely describe the system behavior with respect to a fixed alphabet of actions. This completeness assumption is limiting in the context of software development process best practices which include iterative development, adoption of use-case and scenario-based techniques and viewpoint or stakeholder-based analysis; practices which require modeling and analysis in the presence of partial information about system behavior.