Optimization of production layout in manufacturing can be achieved through process improvement methods. Lean manufacturing is a common process improvement method that has been implemented by many originations and proven successful outcomes. Lean manufacturing is used to identify, analyze, and optimize internal material flow. In this paper, we discuss the implementation of Lean process improvement to optimize production flow in forging industry. The study is conducted in a custom steel forge shop that utilizes 2,000 ton open forge dies, 11 heat treat furnaces, and 5 quenching stations to manufacture large metal parts for oil and gas, military, mining, automotive, and aerospace industries. Currently, the shop is facing issues in the efficiency of the product flow and plant layout. Three production areas of interest are considered while re-evaluating the plant layout. Proposed changes are analyzed based on distance and proximity importance. The layout alternatives are compared based on Net Present Value (NPV) and payback period. The final results show the proposed changes will reduce product travel time as well as relieve bottlenecks in the shipping bay.