Mechatronic design tasks of complex products often require the collaboration and teamwork of several design engineers with special knowledge and skills from the different disciplines involved. Analyzing such design team activities during the development of mechatronic systems is important to improve the efficiency of the process. Evaluation criteria may be defined e.g. with respect to the complexity of necessary interactions between the domain-specific design teams or regarding the number of iterations during the design process. In this context it is necessary to describe the complex structure and hierarchy of the product, which finally allows the use of product data management functions for simultaneous engineering. In this paper the design activities in the development process of mechatronic systems will be analyzed. Different aspects, such as design team activities, mechatronic design models with their hierarchical structure, computer aided support of design tasks are considered for the evaluation and support of the design process. These considerations want to contribute to an increase of efficiency and effectiveness of the design process itself.