A formal kinetic model of lipid layer formation at an interface in contact with a liposomal suspension is developed and investigated. Neglecting diffusion (for sufficiently high bulk concentrations) the kinetic scheme consists of two consecutive processes: (I) irreversible transformation of 'soluble' intact vesicles from the 'subsurface' layer into 'adsorbed' ones ('defected' or 'ruptured' liposomes, 'mesophases'); and (II) irreversible transformation of the 'adsorbed' vesicles into a lipid monolayer. The resulting set of two differential equations is analyzed making use of the 'steady-state concentration' approach (with 'adsorbed' vesicles as intermediate compound). Numerical results illustrate the predicted kinetic behavior which depends on the relative magnitude of the rates of the two consecutive processes. Approximate analytical solutions in the case of a much slower process I are obtained in some limiting cases. The model is used to estimate rate constants from previously established experimental kinetic data at the air/water interface.