BA470_ 2Discussions Problems 3-1 (Do not create p-chart)
This discussion question will not be like previous discussion questions. Your grade will be based primarily upon participation and perseverance. This is the place where we will all learn together how to create and interpret control charts. If you don't understand something, someone else will help you. If you do understand, then you are expected to demonstrate this knowledge by helping someone else.
The assigned problem is 3-1 on page 136, with one major exception. Do not create a p-chart. As was described in the paper http://www.spcpress.com/pdf/DJW233.pdf (Links to an external site.) It is more robust to use Individuals and Moving Range (I-MR) charts instead of p-charts or c-charts. Please analyze the data provided in problem 3-1 as I-MR charts. Please create and analyze the charts. And please always use 3 sigma limits for your analysis.
I want you to first use the ASQ Excel template provided. The asq-control-chart template is available at the Chapter 3 module. The only thing that you need to add is the data. The template is currently populated with four data points, simply as a placeholder. Please type or paste your data over top of these data. Please notice that each column is only 25 lines long. If you have more than 25 data points, then you must use the second column and so on. Please notice under the Instructions that you have the option to choose the subgroup size. Since we are only doing I-MR charts, the the subgroup size should remain as One. If you were to do and X Bar and Range chart, as described beginning on page 119, then you would change the subgroup size accordingly. Please also notice that the control charts actually show lines for One Sigma Limit (short dash line), Two Sigma Limit (long dash line), and Three Sigma Limit (solid line). While the book argues that occasionally you might consider a two sigma limit, this is not considered to be best practice. You are advised to base your analysis upon three sigma limits, as originally devised by Shewhart.
The sooner you begin to post your work, the sooner and more that you can get assistance from me or from a fellow student. If you wait until the weekend, then you may get less help. By learning how to create and analyze a control chart here in this discussion forum, then you will be prepared to do the homework.
Construct a I-MR chart for the company that describes 99.74% of the random variation in the process, and indicate if the process seems to be out of control at any time.
The process seems to be out of control when there was 26 defectives found in sample 23 and 3 defectives found in sample 3 because these two points are outliers for the Three Sigma Limit.