turn on suggestions

Auto-suggest helps you quickly narrow down your search results by suggesting possible matches as you type.

Showing results for

- JMP User Community
- :
- Discussions
- :
- Discussions
- :
- Re: cpK/ppk

Topic Options

- Subscribe to RSS Feed
- Mark Topic as New
- Mark Topic as Read
- Float this Topic for Current User
- Bookmark
- Subscribe
- Printer Friendly Page

- Mark as New
- Bookmark
- Subscribe
- Subscribe to RSS Feed
- Permalink
- Email to a Friend
- Report Inappropriate Content

May 23, 2017 5:21 AM
(1977 views)

Is it correct to calculate cpk when I have no subgroup in the process data (grouping=1), meaning the sampling is continous, like tablet weight taken one after the other in one lot? How is cpk calculated in this case (the withingroup variation)?

Solved! Go to Solution.

1 ACCEPTED SOLUTION

Accepted Solutions

Highlighted
Solution

- Mark as New
- Bookmark
- Subscribe
- Subscribe to RSS Feed
- Permalink
- Email to a Friend
- Report Inappropriate Content

May 23, 2017 1:00 PM
(3823 views)

Correct? That's a different question. The 'correctness' of an approach is dependent on many aspects to the process capability analysis problem. For example: 1. Does your process data exhibit any evidence of assignable cause variation? 2. Does your data appear to be normally distributed? The answer to these questions influences the approach that is optimal for calculating process capability indices over and above the sheer mathematics associated with the reference in my first reply.

3 REPLIES

- Mark as New
- Bookmark
- Subscribe
- Subscribe to RSS Feed
- Permalink
- Email to a Friend
- Report Inappropriate Content

May 23, 2017 12:56 PM
(1954 views)

Here's a reference for you in the JMP Online Documentation.

http://www.jmp.com/support/help/13/Capability_Analysis_2.shtml#1161749

As of January 2018, use this link:

http://www.jmp.com/support/help/13-2/Capability_Analysis_2.shtml#1161749

Highlighted
Solution
Correct? That's a different question. The 'correctness' of an approach is dependent on many aspects to the process capability analysis problem. For example: 1. Does your process data exhibit any evidence of assignable cause variation? 2. Does your data appear to be normally distributed? The answer to these questions influences the approach that is optimal for calculating process capability indices over and above the sheer mathematics associated with the reference in my first reply.

- Mark as New
- Bookmark
- Subscribe
- Subscribe to RSS Feed
- Permalink
- Email to a Friend
- Report Inappropriate Content

May 23, 2017 1:00 PM
(3824 views)

- Mark as New
- Bookmark
- Subscribe
- Subscribe to RSS Feed
- Permalink
- Email to a Friend
- Report Inappropriate Content

May 24, 2017 2:59 AM
(1934 views)

Thank You

Data are normal distributed with no assignable cause variation. I assume the answer I was looking for (found in Process Capability in JMP 2012) is that if I do not group data JMP will automatically use moving range subgroup size 2 to calculate cpk.

KR