Life Cycle Assessment provides a well-accepted methodology for modelling environmental impacts of human activities. This method-ology relies on the decomposition of a studied system into interdepen-dent processes. Several organisations provide processes databases con-taining several thousands of processes with their interdependency links. The usual work-flow to manage those databases is based on the manip-ulation of individual processes which turns out to be a very harnessing work. We propose a new work-flow for LCA inventory databases main-tenance based on the addition of semantic information to the processes they contained. This method eases considerably the modelling process and also offers a more understandable model of the dependencies links. In this paper, we explain our approach and some key parts of the im-plementation. We also present a case study based on the U.S. electricity production and an experiment on the scalability of our implementation.