Despite much research activity there is widespread failure to use available computer programs for planning the layout of manufacturing facilities. There appear to be two reasons for this: (a) the widely held opinion that an experienced planner can produce acceptable layouts based on his own subjective judgement, and (b) ignorance of the potential benefits of computer-aided techniques. This paper reports the results of an extensive investigation into the performance of both human planners and computer algorithms on a standard set of layout problems. Attention is drawn to the important concepts of flow dominanceFand problem complexity. Well known computer programs such as CRAFT and CORELAP were included in the research as well as new programs developed by the authors. Wherever possible, results are expressed in a non-dimensional form so that those responsible for layout planning can select the technique most suited to their particular application.