Explanation
According to the CTSC Exam Content Manual1, Six Sigma is a methodology that aims to improve the quality and performance of processes by reducing variability and defects. Six Sigma uses various tools and techniques to measure, analyze, and control the variation of the forecast and the demand over time for products and services. Some of these tools include control charts, histograms, Pareto charts, scatter plots, and regression analysis. Therefore, Six Sigma is the best tool to use for this analysis. Option A, Lean, is a methodology that aims to eliminate waste and increase value in processes by applying principles such as pull, flow, and continuous improvement. Lean does not focus on measuring and reducing variability of the forecast and the demand. Option C, TOC, is a methodology that aims to optimize the performance of a system by identifying and eliminating the constraints or bottlenecks that limit its throughput. TOC does not focus on measuring and reducing variability of the forecast and the demand. Option D, TQM, is a methodology that aims to achieve customer satisfaction and organizational excellence by involving all stakeholders in the continuous improvement of processes and products. TQM does not focus on measuring and reducing variability of the forecast and the demand.