Optimal design refers to the process of creating or selecting the best possible design for a specific system, process, or product. This involves identifying the most efficient and effective combination of variables, parameters, or components to achieve a desired outcome while minimizing costs, resource usage, or other constraints. Optimal design often involves mathematical modeling, simulation, and optimization techniques to find the optimal solution that meets the desired criteria. This research area is widely used in engineering, operations research, and other fields to improve the performance and efficiency of systems and processes.