A Decision Support Model in Additive Manufacturing and CNC Machining

Additive manufacturing (AM), or 3D printing, is a manufacturing method where components are produced by successively adding material to the product layer by layer, unlike traditional machining where material is subtracted from a workpiece. There are advantages and disadvantages with both methods and it can be a complex problem to determine when one method is preferable to the other. The purpose of this study is to develop a decision support model (DSM) that quickly guides the end user in selecting an appropriate method with regards to production costs. Information is gathered through a literature study and interviews with people working with AM and CNC machining. The model takes into consideration material selection, size, times, quantities, geometric complexity, post-processing and environmental aspects. The DSM was formulated in Microsoft Excel. The difference in costs between each method in relation to quantity and complexity was made and compared to the literature. The margin of error is low, around two to six percent. The conclusion of the study is that AM will not replace any existing manufacturing method anytime soon. It is, however, a good complement to the metalworking industry, since small, complex parts with few tolerances benefits from AM. The system supports well for single and batch production, which helps businesses choose the best, efficient and economical way for manufacturing.