The European Integrated Pollution Prevention and Control (IPPC) directive compels the more polluting industries to apply Best Available Techniques (BAT) in order to reach an adequate level of environmental protection. In Europe, despite the difficulty of implementing the IPPC directive, there is nowadays an increasing endeavour to develop methodologies for quantitative integrated assessments of pollution, improve the understanding and application of BAT at the installation stage and facilitate their selection for European Reference Documents. The methodology proposed in this article aims at helping stakeholders (industrialists, authorities) deal with the update of their exploitation licence (i.e. in this case, the French technical report). Taking into account the local context of the studied companies, the methodology focuses on the evaluation of existing BAT techniques and provides a general framework for the assessment of production units and management processes. The methodology is carried out as a four-step procedure involving an environmental and risk performance assessment tool and an evaluation grid for the production unit. Each production unit is rated through an evaluation grid made of six levels of compliance with the performance of BAT. The aggregation of these marks allows the comparison to the IPPC objectives. Finally, the applicability of this qualitative assessment has been validated through several metal finishing facilities.