In this paper the machine layout problem with a linear single-row flow path in automated manufacturing systems is investigated. Traditional machine layout approaches can produce an inappropriate layout design because they often do not consider flow path characteristics, such as flow path configuration and feasible flow path direction. This paper investigates the effects of such flow path characteristics on machine layouts. There are six flow-line analysis methods reported in the literature. Of these, the two best methods (FLA-5 for bidirectional flow lines and FLA-6 for unidirectional flow lines) are considered here. Two heuristic search algorithms, one combining FLA-5 and a genetic algorithm and other combining FLA-6 and a genetic algorithm, are proposed. A wide variety of data Sets are used to test the proposed algorithms.