Six Sigma and Process Capability are closely related concepts in Operations Management that focus on improving quality and reducing defects. However, they differ in terms of scope, objectives, methodology, and application. While Process Capability measures the ability of a process to produce output within specified limits, Six Sigma is a comprehensive quality management methodology aimed at achieving near-perfect performance by reducing process variation and defects. Six Sigma is a data-driven approach developed to improve organizational performance through continuous process improvement. It seeks to reduce defects to a level of no more than 3.4 defects per million opportunities (DPMO). It follows the DMAIC methodology—Define, Measure, Analyze, Improve, and Control—for improving existing processes. Six Sigma emphasizes customer satisfaction, cost reduction, process standardization, and continuous improvement. It involves trained professionals such as Green Belts, Black Belts, and Master Black Belts who lead improvement projects using statistical tools and problem-solving techniques. Process Capability, on the other hand, is a statistical measure used to determine whether a process is capable of producing products that meet customer specifications consistently. It compares the natural variation of a process with the specification limits established for a product. Common capability indices include Cp, Cpk, Pp, and Ppk. A higher capability index indicates a more capable process with fewer chances of producing defective products.