What is the purpose of using control charts in quality control?

The use of control charts in quality control is primarily aimed at monitoring performance and identifying trends over time. Control charts serve as a statistical tool that allows analysts to visualize how a process behaves in relation to predetermined control limits. By plotting data points over time, it becomes easier to detect variations in process performance, whether they are due to common causes (natural fluctuations within the process) or special causes (unexpected changes in the process).

When a control chart shows data points that trend outside of the established control limits, it signals that there may be a problem that needs investigation. This allows for proactive decision-making to improve processes, maintain quality standards, and reduce variability, which ultimately leads to better overall product quality.

The other options do not align with the primary function of control charts. Determining batch sizes, testing physical properties, or establishing safety regulations are not the main objectives of control charts. Rather, these tasks serve distinct purposes in quality assurance and regulatory compliance that do not directly involve the ongoing monitoring and analysis of process performance over time.