Abstract
Although complex designs are acknowledged to be more suitable for fabrication with additive manufacturing, there is no formalized definition of what makes a geometry sufficiently complex and accordingly appropriate for additive manufacturing. This lack of a standardized definition represents a challenge for engineers and designers. In this context, the objective of this study is to evaluate the role of part geometry in manufacturing decisions and to understand the criteria influencing the selection of a manufacturing process. This research used semi-structured interviews with 11 experts and a survey with 37 novices to gather data. Through ten questions, participants were requested to evaluate ten shapes of parts without further information and speculate on their suitability for additive manufacturing. It emerged that some of the experts stressed batch volume, material, part size, mechanical properties, cost, and material waste as fundamental criteria for selecting a manufacturing process, while novices did not consider material waste and cost as critical aspects. Part geometry was overall given secondary importance unless the part included specific features such as thin walls, lattice structures, and optimized topologies, where the selection leant towards additive manufacturing for both experts and novices. The latter preferred additive manufacturing (70% of the answers) more frequently than the former (54%). Overall, this study highlights the differences in decision-making criteria between experience levels and underlines the need for a formalized framework to evaluate geometric suitability for AM.