The operability of azeotropic distillation columns with multiplicity is analysed during start-up by dynamic simulation. Different steady states can be reached by applying different start-up configurations and/or policies. The well-known benzene-heptane-acetone (BHA) system is studied. The process by which the column reaches these steady states can be seen through the examination of profile evolutions corresponding to the given start-up policies. Indeed, a clear partition of the start-up policies space yielding different solutions is achieved. Some properties of this space are explained and start-up critical values can be identified. Finally, some guidelines for start-up supervision are outlined for the study case.