Reengineering process is intended both for users and equipment designers. It may redefine the process management such as thermal constraints applied to food product in order to enhance their safety. The objective of this study is to develop models able to predict the thermal history of food products all along its processing chain and to study the influence of process parameters on the microbial growth. In this purpose, these models are coupled with microbial models in order to assess the impact of process control parameters on the final concentration of micro-organisms. The studied case corresponds to the processing of meals (beef in sauce) prepared for differed consumption in a central kitchen at a French Parisian hospital. Each step of the process is modelled by using a deterministic thermal approach. However, the input parameters of the model are often random variables. The input parameters of the models include technical features (e.g. cooling and heating capacity, airflow, thermal inertia effects of the equipment, thermal capacities of the products) as well as other process parameters set by the operators (e.g. duration of cooling down and of warming up, thermostat setup, charge of the equipment). According to the operator's influence on these last parameters, they could be considered as random. A sensitivity analysis showed that the reheating step is one of the important key points to achieve targeted food safety objectives. It also showed that the cooling rate in the cooling cell is another key parameter to be accounted for.