**Abstract**

Metal Additive Manufacturing (MAM) is delivering a new revolution in producing three-dimensional parts from metal-based material. MAM can fabricate metallic parts with complex geometry. However, this type of Additive Manufacturing (AM) is also impacted by several issues, challenges, and defects, which influence product quality and process sustainability. In this chapter, a review has been made on the types of small to medium-sized metallic parts currently manufactured using the MAM method. Then, investigation was undertaken to analyze the defects, challenges, and issues inherent to the design for additive manufacturing, by using MAM method. MAM-related obstacles are discussed in depth in this chapter and these obstacles occur in all size of metal printed parts. The reasons and solutions presented by previous researchers of these obstacles are discussed as well. A potential approach based on the author's knowledge and analysis for solving these issues and challenges is suggested in this chapter. Based on the author's conclusion, the MAM is not limited by part size, material, or geometry. In order to validate the potential solutions developed by the author of this work, performing actual MAM process is required and a local visit to manufacturing factories are also important to visualize these challenges and issues.

**Keywords:** metal additive manufacturing, powder bed fusion, direct metal deposition, MAM alloys, MAM problems, 3D printing
