The authors briefly recapitulate the face-to-face composition (FFC) model for the representation and manipulation of topological and geometric entities. They then summarize L.S. Homem de Mello’s and A. Sanderson’s (1988) proposal for assembly planning. It is shown that the assembly AND/OR graph proposed by L.S. Homem de Mello and A. Sanderson for task planning is an efficient data structure showing all possible assembly sequences. It can be obtained directly from the FFC model by a sequence of component-merging operations