In this paper, we develop a conceptual model that integrates the microsimulation and the multi-agent systems in the urban goods distribution processes. The proposed model, which it is defined between the agent-based microsimulation models, allows to analyze the different behaviors and actions that are the result of an urban freight distribution process, facilitating the decision making to improve the efficiency of the logistic process. The model is formulated as a multi-layer urban freight distribution network which involve the street city network and the microsimulation of passenger trips, the use of a distribution center, the design of initial static pick-up and delivery routes, the behaviors of the agents of the system and their interactions that give feedback to the model, and finally assess the impact of the agents in the improvement of the re-routing optimization process at urban freight distribution, according to the multiple types of dynamics variables such as dynamic travel time by traffic conditions in different travels.