Can we rely on the analysis of flux decline to evaluate the risks of a filter media to be clogged during filtration of a given particle suspension? This important issue can be dealt with a macroscopic approach described in this paper. We seek to identify and quantify the successive prevailing mechanisms which occur during a filtration run, directly and solely from experimental flux data. This is achieved from the collection of experimental data (filtrate volume V vs. time t) and the use of the differential equation (d(2)t/dV(2)) = k(dt/dV)(n). A methodology is then proposed to define and validate experimental procedures with the purpose of quantifying occurring fouling mechanism. For the purpose of illustrating its valuable impact for a bench marking procedure, the methodology has been applied on a model system composed of a bentonite suspension and a series of microfiltration membranes of different structures. (C) 2008 The Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.