Final answer:
A U-chart can be used to construct a control chart for Millie's Fine Foods' customer complaints. The chart will include control limits set at three standard deviations above and below the mean number of daily complaints to monitor for potential process issues.
Step-by-step explanation:
To construct the appropriate control chart for tracking customer complaints at Millie's Fine Foods using three-sigma control limits, we first need to gather the data representing the number of complaints per day for the ten-day period. The type of control chart used typically depends on the data's nature; in most service industries, a P-chart (proportion control chart) or a U-chart (count of defects per unit control chart) may be used to monitor the process.
For the given scenario regarding customer complaints, we might use a U-chart, given that we are dealing with counts of events (complaints) over a constant sample size (daily customer interactions). In creating the U-chart, we would calculate the mean number of complaints per day, and then establish control limits at three standard deviations above and below the mean, using the formula μ ± 3σ, where μ is the mean and σ (sigma) is the standard deviation of the data collected.
To ascertain whether the process is in control, we would then plot the daily complaints on the U-chart and verify if any points lie outside the established control limits, which would indicate a potential issue with the process that may require attention.