The Commissioning sector has been trying to implement the prioritization of the equipment's, instrumentation and piping installation and assembly activities based in its systems and subsystems. In general, the prioritization of these activities is carried out differently between the Construction and Assembly sector and the Commissioning sector. Thus, this work aims to analyze which of these prioritization approaches is the most effective in terms of project final delivery time, as it is verified that there are many conflicts regarding the prioritization of these activities between these two sectors. That said, it’s important to state that the Construction and Assembly sector prioritizes the quantitative measurement of a certain period of work aiming financial responses, while the Commissioning sector prioritizes activities that are really essential and that impact the deployment of the FPSO (Floating Production Storage and Offloading) platform, so that it can start the process of obtaining the first oil. Hence, for the accomplishment of this work, the Experimental Study Method was used, in which 5 common subsystems between 2 similar FPSO platform projects were analyzed. In each case the prioritization of the installation and assembly activities of the equipment, instruments and pipes was elaborated respectively by the Construction and Assembly sector (project A) and by the Commissioning sector (project B). Comparative rundown curves were generated between projects A and B, where the manpower allocation efficiency generated by the Commissioning through the priority systems was verified.