(Solution) - In the book Tools and Methods for the Improvement of -(2025 Original AI-Free Solution)

Paper Details

In the book Tools and Methods for the Improvement of Quality, Gitlow, Gitlow. Oppenheim. and Oppcnheim discuss a resort hotel's efforts to improve service by reducing variation in the time it takes to clean and prepare rooms. In order to study the situation, five rooms are selected each day for 25 consecutive days, and the time required to clean and prepare each room is recorded. The data obtained are given in Table 17.6.
a. Calculate the subgroup mean  and range R for each of the first two subgroups.

c. Find the control chart constants A2 and DA for the cleaning and preparation time data. Does D, exist? What does this say?
d. Find the center line and control limits for the chart for these data.
e. Find the center line and control limit for the R chart for these data.
f. Set up (plot) the  and R charts for the cleaning time data
g. Are the  and R charts in control? Explain.