CASE #3
Ricardo’s Widgets
Ricardo’s Widgets makes a critical part for a popular brand of smart watch. Consider the data for
15 samples of size 4 of a key dimension for the part, shown in the MGMT_368_Case_3_Data.xlsx.
Specifications of that key dimension are 0.110 ± 0.02. Use the template for x-bar and R charts used
in “La Ventana Example” available on Blackboard to answer the following questions.
Please upload your individual Microsoft Excel solution file on Blackboard by the due date. Each
question must be answered on a separate sheet of the same Excel file.
Questions.
1) What are the values of the Upper Control Limit (UCL), Lower Control Limit (LCL),
and Center Line (CL) of the R chart based on the sample dataset given? (6 points)
2) What are the values of the Upper Control Limit (UCL), Lower Control Limit (LCL),
and Center Line (CL) of the x-bar chart based on the sample dataset given? (6 points)
3) Plot the R and x-bar charts using the template. (4 + 4 = 8 points)
4) Is the process in statistical control? Why or why not? Explain. (4 points)
5) Using the template, compute the process capability using actual sample standard
deviation: what are the values of Cp and Cpk? Is the process capable? (2 + 2 + 2 = 6
points)
