Which of the following best describes a control chart?

A control chart is best described as a visual representation of statistical process control. This tool is specifically designed to monitor the stability and performance of a process over time by plotting data points in a time-ordered sequence. The control chart displays upper and lower control limits, which help identify variations in the process that may indicate whether it is in control or out of control. By analyzing these variations, organizations can detect trends, shifts, or unusual patterns that require further investigation or corrective action.

The other options focus on different aspects of business and management. Tracking inventory levels involves managing supply chain elements rather than statistical control. A graphical comparison of competing strategies typically falls under marketing or competitive analysis rather than process monitoring. Lastly, methods for costing operations relate to financial assessment and do not involve tracking process stability or performance in a statistical manner. Thus, the emphasis on statistical process control is what makes the visual representation of control charts the most fitting description.