In this paper an overview of human models and their applications is presented. The constraints and objectives of use of these models for evaluating the performance of manufacturing systems are emphasized and it is shown that the conventional human models are not adapted to respond to new analysis requirements. To provide a dynamic and an adaptive model, a multi-agent/multi-scale architecture is proposed which integrates various human models in a single framework. The components of the performance analysis agent, one of the human modeling agents are described and their characteristics for applying in manufacturing systems are explained. This approach can be used for modelling and analyzing human performance in computerized 3D platforms during design of manufacturing systems