Additive manufacturing (AM) or 3D printing of metals promises a significant impact on the upcoming industrial revolution “Industry 4.0" as it is considered one of its main pillars. However, some challenges related to high initial cost and the fabricated part's quality still existed. Selective laser melting (SLM) is one of the effective techniques used for additive manufacturing to fabricate metal products. This paper presents the impact of different post-processing treatments on the microstructure and surface quality of the AlSi10Mg parts fabricated using SLM. This work illustrates the analytical view of the results obtained from two studies in a previous work by the author. A process map is presented for thermal post-processing treatment to customize the required quality and material characteristics of the AlSi10Mg parts. In addition, the shot peening results in a significant improvement for both surface roughness and hardness is illustrated. This work is a part of developing the manufacturing process of additively manufactured lightweight parts in some critical applications specifically for the metallic mirrors used in high power laser systems or wide view space telescopes.