A generalized theory has been proposed for a crossflow membrane filtration process, comprising of intermediate pore blocking followed by cake formation, in sequence. A phase space plot has been generated to identify the three filtration domains namely, pore blocking dominant, comparable resistances and cake dominating process. It is found that the crossflow velocity (in terms of steady state flux) has significant effect on the onset of the cake formation. It is observed that the intermediate pore blocking has very narrow region of dominance, so most experimental data are likely to lie in the cake controlling region. The operator can effectively control the characteristics of filtration by changing the crossflow velocity and transmembrane pressure. (C) 2010 Elsevier B.V. All rights reserved.