In: Operations Management
8. What is the X bar chart used for?
9. What is the first step in the construction of the X bar chart?
11. What is the second step in the construction of the X bar chart?
13. What is the third step in the construction of the X bar chart?
14. What is a homogeneous sub-group?
Ans 8:
The X-bar chart is a type of Shewhart control chart that is used to monitor the arithmetic means of successive samples of constant size, n.X-bar charts are used to monitor the mean of a process based on samples taken from the process at given times (hours, shifts, days, weeks, months, etc.).
Ans 9:
The first step in the construction of the X bar chart is to determine the sample size, n, and frequency of sampling. It also involves considering the cost of sampling, required resources, and balancing with minimizing time (and produced units) between measurements.
Ans 11:
The second step in the construction of the X bar chart is to
collect enough samples to create reasonable estimates of the mean
values of
. Also, the data should be kept in time sequence following the time
of the sample selection, which should be in the same order of
manufacture.
Ans 13:
The third step in the construction of the X bar chart involves
calculating the average of each set of samples i.e.
.