The foundational theory underlying Operations Management encompasses various principles aimed at optimizing processes, resources, and outcomes within organizations. Key theories include Taylorism, which emphasizes efficiency through scientific management; Fordism, focusing on assembly line production and mass consumption; Total Quality Management $($TQM$),$ emphasizing continuous improvement and customer satisfaction; Lean Production, aiming to minimize waste and maximize value; and Six Sigma, focusing on reducing defects and variability. These theories provide frameworks for analyzing, improving, and innovating operational processes across industries.