###### Abstract
Their conclusion indicated that elevated values of  
\begin{table}
\begin{tabular}{c c c c c} \hline
**Ref. ** & **Year** & \begin{tabular}{c} **Objectives** \\ **to Be** \\ **Optimized** \\ \end{tabular}  & \ \begin{tabular}{c} **Process** \\ **Parameters** \\ \end{tabular}  & \begin{tabular}{c} **Description of the Study** \\ \end{tabular}  \\ \hline
[23] & 2021 & \begin{tabular}{c} Shrinkage \\ and warpage \\ \end{tabular}  & \ \begin{tabular}{c} Packing time, mold \\ temperature, packing \\ pressure, melt temperature, \\ and cooling temperature \\ \end{tabular}  & \begin{tabular}{c} This study concentrated on the simulation process of injection molding and optimization for automobile instrument parameters in embedded systems. \\ This study involved the warpage optimization of molded parts with straight-drilled and conformal cooling channels. This research utilized multiple optimization approaches including response surface methodology (RSM), Glowworm Swarm Optimization (GSO), and genetic algorithms (GAs). The researchers aimed to optimize the warpage of molded parts by comparing the effectiveness of different cooling channel designs, specifically straight-drilled channels versus conformal cooling channels. \\ [PERSON] et al. conducted a study on the numerical optimization of multistage packing pressure profiles in plastic injection molding and validated their findings through experimentation. The researchers aimed to optimize the packing pressure profile during plastic injection molding. Packing pressure is a critical parameter that influences the final properties and dimensions of molded parts. The authors reported that the proposed procedure can reduce warpage and cycle time, as well as the clamping force. \\ \end{tabular}  \\
these parameters typically led to a reduction in surface roughness. The authors of [30] investigated the replication of the surface microstructure during the molding process, particularly in cases where the intricate surface pattern of the mold was transferred onto the molded product through a complex mechanism. Their findings highlighted that molding parameters, particularly the mold temperature, affected the replication of the desired topology of the product surface. The mold cavity surface temperature significantly affects the roughness of the injection-molded part, as noted by [PERSON] et al. in reference [31]. Their conclusion was that with increasing mold temperature, there is a decrease in the roughness of the product. [PERSON] et al. improved the surface quality of a molded product by utilizing induction heating to regulate mold temperature. [PERSON] et al. demonstrated their success in reducing the roughness of injection-molded products by incorporating an insulation layer of polytetrafluoroethylene (PTFE) between the mold and the plastic melt [32]. This PTFE layer maintained the melt temperature above the plastic crystallization temperature. [PERSON] carried out a study examining how the surface roughness of injection-molded polypropylene (PP) components is influenced by factors such as holding pressure, holding duration, injection rate, and cooling duration [33]. In this study, it was reported that the mold surface played the most prominent role in determining the roughness of the part, followed by injection speed. [PERSON] and his team conducted a study focused on optimizing injection molding process parameters to minimize surface roughness in molded products [34]. Their findings indicate that both injection temperature and pressure play significant roles in affecting part surface roughness. This literature review clearly indicates that the parameters of the injection molding process have a direct impact on the surface roughness of molded products. More studies are, however, still required to provide further insight into this topic. Specifically, research should focus on establishing a correlation between injection molding parameters and surface roughness, as well as examining the association between surface roughness and other defects like warpage and volumetric shrinkage.