Which statistical tool is commonly used in Six Sigma to analyze processes?

Control charts are a vital statistical tool in Six Sigma for analyzing processes because they help monitor process performance over time by displaying data points and indicating variations. They are designed to distinguish between common cause variation, which is inherent to the process, and special cause variation, which arises from specific circumstances. By tracking these variations, teams can identify trends, shifts, or any unexpected results that may indicate a need for intervention, thus ensuring the process remains stable and under control. The use of control charts supports the Six Sigma objective of maintaining consistency and quality in processes.

The other options, while useful in various contexts, do not specifically contribute to the analytical framework central to process improvement in Six Sigma. SWOT analysis, for example, is strategic planning related to identifying strengths, weaknesses, opportunities, and threats, but it does not focus on the quantifiable aspects of process performance. Similarly, PEST analysis examines external environmental factors impacting an organization, and market segmentation involves categorizing potential customers based on varying characteristics. These tools are more oriented toward strategic analysis rather than the statistical evaluation needed for quality control and process management.