What is the main focus of an R-chart in quality management?

• A. To measure the proportion of defective items
• B. To monitor the range within a process
• C. To analyze the defect rate over time
• D. To assess the capability of the entire process

Answer: (B)

The main focus of an R-chart, which is a type of control chart used in quality management, is indeed to monitor the range within a process. The R-chart specifically tracks the variability of a process by measuring the range of values in a sample. By assessing the range, it helps identify whether the process is behaving consistently over time or if there are variations that could indicate potential issues in quality.

Monitoring the range helps in understanding the dispersion of the process and assists in maintaining a process in a state of statistical control. This insight is crucial for quality control, as excessive variability may lead to a higher likelihood of producing defective items. While the other choices present important aspects of quality management, they do not accurately reflect the primary objective of an R-chart, which is focused on tracking variability rather than defect rates, proportions of defects, or overall process capability.