Re: PMHUB-G Control Limits, predefined by Definition?

Hi Paul,

thanks for your answer. Although it does not answer my
question completely the link is a very nice help for understanding
parameters of normal ditributions.

Regarding my question I have done more internet research and
came to the following conclusion:

In general control limits are chosen as +/- 3 sigma, also PMBOK
Guide uses this definition. This is based on the widely used
control chart by Walter A. Shewhart. Other control charts exist
with different control limits (see http://en.wikipedia.org/wiki/Control_chart).

At the end the control chart in PMBOK Guide is a correct
example of a control chart but shows different control limits than
mentioned in the glossary.

Best regards
Chris

On 27 Nov., 18:37, "Paul D. Giammalvo" <pauldg...@gmail.com> wrote:
> Control limits are a calculated value based on the underlying data. It is
> +/- 3 Standard Deviations from the mean and while the definition doesn't
> change (always +/- 3 sigma) the actual distance from the mean will change,
> depending on what the value of each sigma is.
>
> I am in the Lagos, Nigeria airport right now and don't have access to my
> latest PMBOK Guide to check the picture, but Google on Z tableshttp://davidmlane.com/hyperstat/z_table.htmland you can start to get an
> idea that as the value of the standard deviations increases, the shape of
> the normal distribution will change. (Flatten out and spread wider at the
> sigma increases)
>
> BR,
> Dr. PDG, Lagos, Nigeriahttp://www.build-project-management-competency.com
>
>
>
> -----Original Message-----
> From: pmhub@googlegroups.com [mailto:pmhub@googlegroups.com] On Behalf Of
>
> Chris
> Sent: Saturday, November 27, 2010 23:10
> To: PMHUB - The largest PM group in Googlegroups!
> Subject: PMHUB-G Control Limits, predefined by Definition?
>
> Hi all,
>
> I am wondering about whether the wording "control limits" means a
> specific deviation from mean.
>
> See PMBOK Guide p.430:
> "Control Limits. The area composed of three standard deviations
> oneither side of the centerline."
>
> Does this mean, that my upper and lower contorl limits have always the
> same distance from mean in a control chart?
>
> If yes, is picture on p.196 not correct?
>
> 2 days before Exam and repeating the Glossary :-)
> Chris
>
> --
> To post to this group, send email to PMHUB@googlegroups.com
> To unsubscribe from this group, send email to
> PMHUB-unsubscribel@googlegroups.com
> For more options, visit this group athttp://groups.google.com/group/PMHUB?hl=en- Zitierten Text ausblenden -
>
> - Zitierten Text anzeigen -

--
To post to this group, send email to PMHUB@googlegroups.com
To unsubscribe from this group, send email to PMHUB-unsubscribel@googlegroups.com
For more options, visit this group at http://groups.google.com/group/PMHUB?hl=en