What is the primary use of run charts?

Run charts are primarily utilized to track changes in data over time, providing a visual representation of how a particular measurement or process variable behaves over a specific period. This tool is crucial for identifying trends, patterns, and shifts in data, enabling organizations to make informed decisions based on historical performance.

By plotting data points in chronological order, run charts facilitate the identification of any fluctuations that may correlate with changes in processes or external factors. This means a company can observe how improvements or variances occur, and analyze the effectiveness of interventions made during that timeframe.

The other options, while relevant in different contexts, do not accurately reflect the primary function of run charts. Identifying customer preferences relates more to market research tools, creating marketing strategies involves a different set of analytics techniques, and summarizing financial reports typically utilizes various accounting methods rather than continuous time-series measurements represented through run charts.