I'm starting with SPC in my company. To my understanding to run SPC you need first to set up what I call the benchmarks (UCL and LCL) using a set of historical data. Once this defined you plot all new values against those and check for OOC results.

My colleagues use to run statistical on the data and where looking also for OOC points. Doing like this you get moving UCL and LCL. They don't use historical data.

What is correct practice ?

Regards,

Guy

Please excuse my English, it...

Understanding SPC]]>

I was assigned a task in the company I work for related to evaluate control limits from SPC charts periodically (yearly). The evaluation is to determine if control limits recalculation is required... this is easy for me to do in terms of reviewing a few charts... the problem is that there are around 5000 SPC charts in all the plant so my manager is asking me to define a "valid" criteria to choose some charts and evaluate them. At the end we are looking to have SPC charts with...

Control limits evaluation / recalculation]]>

We just had a vice presidential debate. Since my null hypothesis is my dull hypothesis, I submit the following two:

H0: The vice-presidential debate had no effect on voter decision.

HA: The vice-presidential debate changed the minds of voters.

So under the assumption I do all the surveying and statistical math right looking for a changed poll after the debate.....

What does the p-value mean?]]>

Could someone help me with an interpretation of the following Capability Six pack result? Please look at the attached file.

I am aware that there is only 32 observations instead of at least 50, but in this case there are enough to determine that the process needs to be changed.

Individual and Moving Range Charts should be ok. I used in Minitab the Nelson Rules feature and there are any red points. It could be said that the process is stable.

Capability Histogram...

Interpret the capability plot in Capability Six pack]]>

Thanks]]>

I intend to use Minitab, but before using, i would like to know the following (what i can not get from the available videos):

My intension is to evaluate a process - how much an actual process differs from the master measurement. Every measurement has the following format:

------------------------------

Measurement 1:

x ............ ... y

300 ............ 50

350 ............ 55

400 ...............

How to evaluate any significant difference using Minitab]]>

I can select the correct control chart take it further and do descriptive statistics and even process capability study but where I in trouble is commenting on minitab has produced. I have to write a paragraph on whats happening.

Iv tried to find examples online but I'm having no...

Writing a SPC report for managment]]>

I am giving SPC software

It will be useful to the interested

Kedar]]>

Recalculate control limits for every lot?]]>

SPC for tablet/capsule weights. Can it be done?]]>

QAQC's role in SPC charts]]>

note that Quality Digest has closed the comment function for this column.]]>

SPC A-D TEST FAIL]]>

How should I calculate?]]>