In the era where mass production is inevitable, developments in the manufacturing process have helped industries to produce goods in batches of enormous quantities. With the drastic growth in technology, it is crucial to update, and improve assembly lines continuously. This study aims to systematically understand the area where an assembly line needs improvement to enhance its process and productivity. Published articles related to assembly line improvements, lean techniques, and simulation were synthesized exhaustively. A Discrete Event Simulation model of an automated manufacturing company was developed based on the data acquired and observations. Integration of lean techniques along with simulation adds to the effectiveness of the proposed method. Crucial areas that need improvement were identified, and lean techniques such as Kaizen and Poka-Yoke were applied. The efficiency of the proposed improvements was visualized by altering the simulation model. The average WIP was reduced from 87.2 to 81.2, and the cycle time of seven stations was reduced as a result of the implementation of Lean principles. Laser Marking Station (Fixture clamping and Stopper Cylinder) and Pad Printing & Vision Inspection Station witnessed a twofold improvement in the proposed model. There was an improvement in throughput by 7.14%. The study would prove helpful for managers and policymakers to visualize the usefulness of implementing lean techniques with minimal investment.