In Burkina Faso, biofuels represent a great opportunity to address important economic development issues such as modern energy access and dependence on energy imports. Jatr opha Curcas (Jatropha) has been identified as the most suitable feedstock for biofuel industry development. Considering the socio - economic issues and the commitment of the government in the Millennium Development Goals, the most promote d scheme for biofuel sector development is the production of straight vegetable oil (SVO) by small - scale oil plants, based on Jatropha oilseeds cultivation by smallholders. SVO can be directly used as a fuel in stationary diesel engines, through minor adaptations. The sustain ability of the biofuel sector, is submitted to a range of choices concerning conversion technologies, production capacities, processing conditions, and by - products valorisation. Our purpose is to develop a methodology to assess the best system designs towards sustainability criteria that are to be defined through a careful analysis of socio - economic context. A computing tool, called OSMOSE, allow s the implementation of technology models, the simulation and optimization of overall production system. In this paper, we present the techno - economic simulation of a small - scale oil production plant. The results show that the activity can be profitable from a minimum capacity of 100 tons .year - 1 and that maximizing oil recovery leads to very high processing costs. Moreover, the analysis raises (i) the strong importance of seed cake valorisation in the sustainability of Jatropha biofuel systems and (ii) the influence of seedcake's oil content in its valorisation possibilities.