Which methodology is focused on continuous process improvement and effectiveness?

Six Sigma is a methodology specifically designed to improve the quality of process outputs by identifying and removing the causes of defects and minimizing variability in manufacturing and business processes. It employs a set of quality management tools and techniques aimed at continuous improvement while ensuring effectiveness in processes.

The core of Six Sigma revolves around a data-driven approach, typically using statistical methods, to analyze and improve processes. This focus on continuous process improvement is what sets it apart as a robust methodology for enhancing efficiency and effectiveness in various industries.

The other methodologies mentioned do have their respective strengths, but they do not primarily focus on continuous improvement in the same manner as Six Sigma. The Waterfall methodology is mainly a structured project management approach that's linear and sequential, which is not adaptable to continuous improvement. Agile is a framework that encourages iterative development but focuses more on software development and flexibility rather than specifically on process effectiveness. Benchmarking is a comparison process to measure performance against industry bests but does not inherently provide a framework for continuous improvement like Six Sigma does.