|
This thread is carried over and continued in the Current Elsmar Cove Forums 
|
|
|
This thread is carried over and continued in the Current Elsmar Cove Forums
|
The New Elsmar Cove Forums
|
 The New Elsmar Cove Forums
 Statistical Techniques and 6 Sigma
 out of control patterns for non-normal dis.
|
 UBBFriend: Email This Page to Someone! |
next newest topic | next oldest topic |
| Author | Topic: out of control patterns for non-normal dis. |
|
arezoo unregistered |
posted 12 June 2001 12:21 AM
 
Hi A process has a non-normal dis. and we prepare a control chart for that by using normal probablity plot. Is there any "out of control patterns" for these control charts? Maybe it is enough for these control charts only staying in their control limits ? please help me to solve this problem. thanks a lot Arezoo IP: Logged |
|
Ken K. unregistered |
posted 18 June 2001 12:25 PM
A control chart that uses averages does not necessarily need to assume the data to be normally distributed (thanks to the central limit theorem). As long as you are calculating averages for each subgroup AND have subgroup sample sizes of 4-5 or larger, you should do fine regardless of the distribution of the raw data. There has been much debate as the the importance of normality in control charts. This is a no brainer for x-bar charts, not so obvious for some others. The R-chart is less robust against nonnormality. On the other hand, nonnormality with individuals charts violates basic assumption of the method and be cause for concern. IP: Logged |
All times are Eastern Standard Time (USA) | next newest topic | next oldest topic |
  |
Hop to: |
Your Input Into These Forums Is Appreciated! Thanks!
Main Site Search 
