The Object Modeling Technique (OMT), a commonly used object-oriented development technique, comprises the object, dynamic, and functional models to provide three complementary views that graphically describe different aspects of systems. The lack of a well-defined semantics for the integration of the three models hinders the overall development process, particularly during the design phase. Previously, we formalized the object model in terms of algebraic specifications. However, the algebraic specifications only capture the static, structural aspects of a system. They do not explicitly describe the behavior, which is critical for system development especially for the design phase. It is necessary to formalize the dynamic model in terms of the structural descriptions in order to specify and verify the system behavior using rigorous techniques. This paper presents a well-defined formal model for both the object and dynamic models and their integration. The formal model is described in terms of a well-known specification language, LOTOS. Formalization of the graphical notation enables numerous automated processing and analysis tasks, such as behavior simulation and consistency checks between levels of specifications.