Explore the foundational principles and theoretical frameworks within the domain of operations management, elucidating its role in optimizing organizational processes and enhancing efficiency. Investigate the concepts of production planning, inventory management, and supply chain optimization, analyzing their significance in meeting customer demands while minimizing costs. Delve into the theories of quality management and process improvement, examining methodologies like Six Sigma and Total Quality Management $($TQM$)$ in ensuring product and service excellence. Discuss the role of forecasting and capacity planning in strategic decision$-$making, highlighting their impact on resource allocation and operational performance. Furthermore, explore contemporary topics such as lean manufacturing, agile operations, and sustainability in operations management, evaluating their implications for modern organizations and their competitive advantage in the global marketplace. Illustrate with case studies and examples from various industries, demonstrating the application of theoretical concepts in real$-$world scenarios.