The cargo system of FPSO units is of particular interest due to its rigorous operational requirements. In addition to structural and static stability requirements, the offloading operation of FPSO units should satisfy rigorous requirements related to the dynamic behavior of the vessel. In this sense, the cargo offloading process of FPSO units represents a critical aspect related to its design and operation. Unfortunately, due to the great computation effort usually required to analyze complex pipe networks, it is not a common practice to perform the analysis of the cargo system functioning at the design stage. This paper presents the analysis of the offloading operation of a typical FPSO unit. The analysis comprehends the simulation of the operation of the cargo system during the offloading process. The author adopted a new method to the analysis of pipe networks that seems to be more adequate for the analysis of fully branched systems. The results obtained indicate that the simulation of the cargo system operation is a useful tool for the analysis of the offloading process of FPSO units both at the design stage and during site operation.