Human factors integration is often achieved during detailed manufacturing system design phases. Whereas, significant decisions are token when overall primary design is set. Accordingly, this paper introduces a new design framework based on the function–behavior–structure to consider human factors earlier in the design process. The main idea consists in analysing the behavioural interactions between workers and manufacturing equipment driven from the system structure. Relevant human and health related factors to these interactions are then integrated in the analysis. These interactions are model and simulated to assess the system design using specific productivity and working conditions indicators.