This paper presents a swarm intelligence approach for optimal orientation of a part produced by the fused deposition modelling method, with a view to reduce the volumetric errors that are primarily responsible for poor surface finish. A part is oriented in such a way to assist the designer in reducing build time, while at the same time enhancing part quality and orientational efficiency. The conventional approach in optimization of part orientation considers only minimization of the staircase effect in order to enhance the part quality. In the approach used by the present authors, a part is oriented by transforming it about x and y axes and an orientation is selected that not only provides minimum volumetric error and building time but also...