Setting of control limits for characteristics

[former_member263130]

Hello all SAP masters,

We need to set control limits (action as well as warning limits) for characteristics.

Can any one forward me details on the options available, Manual set limit as value in fields or system calculates on the parameters set in configuration and Upper\lower limit set in characteristics.

From information I got, I understand, by some intial run transactions and parameters set for control charts system can set control limits. But I am not sure how to do it......what is this initial run and how to be performed in system.

It would be help if all you masters can explain me or forward me details about control limits.

I hope I was clear about issue but incase if any other information is required then let me know.

Any feedback from all you masters there to resolve this will be great help

Thanks and regards,

Devang

[muhamed_faisal]

Dears

i will great full if anybody can show some tips of how to create control chart in qm module with help of some screen shot

Faisal

[former_member207800]

Hi, Devang.

Good and difficult question in forum.

1) System will require some results to calculate control limts, right?

> Yes, the inspection result like mean value, standard deviation is needed.

So, till system calculates those control limits, how system will valuate results (will it be with specificaiton limits specified at inspection characteristics level),

> Yes, system refer the tolerance(spec. limit) and user valuates manually.

do we have any option of entering preliminary results so that system can control limits on bases of those results and so from very first inspection lot we have control limits for valuation?

> No function in SAP. As I know, user should valuate manually for very first inspection lot.

4) There are three status possible for control charts, 1) New 2) Active and 3) Close. So how this active status is set? If user manually has to set this Active status for each control chart then what is logic behind this, why system does not change status automatically after creation.

> Previously my wrong answer about status. You don't need to change the status into 'active' for automatic process.

As I know, the status change from 'new' to 'active' does not have any effect on other function.

I'm not sure why SAP divide 'new' and 'active'.. But you can change mass at transaction QGC1.

Regards

Luke

[former_member263130]

Hello Luke,

Once again thanks a lot for your descriptive reply.

But I am still not clear (see, how dumb one can be) about activating control charts,

> Previously my wrong answer about status. You don't need to change the status into 'active' for automatic process. As I know, the status change from 'new' to 'active' does not have any effect on other function. I'm not sure why SAP divide 'new' and 'active'. But you can change mass at transaction QGC1.

What you mean by automatic process? Do user has to activate it manually or system will automatically change status to active?

There are couples of more questions I have which I will put under separate thread. And definitely I will like you to help me with those as well 

Best wishes,

Devang

[former_member207800]

Hi, Devang.

It means automatic valuation.

I thought we have to change the status 'active' for automatic valuation, but it was wrong.

If the control limit (action limit) has been calculated before, system valuates the results automatically whatever status.

And system does not change the status. So user should if it is needed.

But I think we don't need to change the status 'active' because there is no problem with status 'new'.

Regards

Luke

[former_member207800]

Hi, Devang.

I can't understand some question but let me answer.

1) SAP will calculate the control limits automatically, but you can change or save the control limits if you check 'change control limits' in configuration.

2) The control limits are calculated based on parameter(sigma), spec. limit, inspection results.

Check the information of each function module for control chart like as 'QRKT_MEAN_VALUE_SHEWHART'.

3) Yes. The SPC inspection means valuation by control limit, not spec. limit.

You should change the status of control chart into 'active' for automatic valuation.

4) SAP will create new control chart if you change the status of control chart into 'close'.

SAP does not create new control chart when status 'new' or 'active'.

Regards

Luke

[former_member263130]

Hello Luke,

Once again thanks for your reply, it was very much useful.

But I still have some doubts so let me rephrase my queries:

1) System will require some results to calculate control limts, right? So, till system calculates those control limits, how system will valuate results (will it be with specificaiton limits specified at inspection characteristics level), do we have any option of entering preliminary results so that system can control limits on bases of those results and so from very first inspection lot we have control limits for valuation?

4) There are three status possible for control charts, 1) New 2) Active and 3) Close. So how this active status is set? If user manually has to set this Active status for each control chart then what is logic behind this, why system does not change status automatically after creation.

Example: In case of productions orders there is option to release produciton orders manually. As on releasing production order system performs many activities in background like creating reservation, creating inspection lot etc. And this gives flexibility of creating many orders at single time and this is require as in production there can be many orders executed simultaneously for same material. But in control chart I dont see any logic why operator has to manually set active status.

I hope this time I was clear with my quesries.

Thanks in advance for your help.

Best wishes,

Devang

[Former Member]

Hi Devang,

I also have the same issue in control chart, need some help.

Did you get the answers for your question below. Can you please let me know your findings.

1) System will require some results to calculate control limts, right? So, till system calculates those control limits, how system will valuate results (will it be with specificaiton limits specified at inspection characteristics level), do we have any option of entering preliminary results so that system can control limits on bases of those results and so from very first inspection lot we have control limits for valuation?

4) There are three status possible for control charts, 1) New 2) Active and 3) Close. So how this active status is set? If user manually has to set this Active status for each control chart then what is logic behind this, why system does not change status automatically after creation.

Thanks

Bob

[former_member207800]

Check the control limit setting of control chart in configuration

SPRO > Quality Management > Quality Planning > Basic Data > Sample, SPC > Statistical Process Control > Define Control Chart Type

If you know the calculation of sigma, you can set it easily.

Regards

Luke

[former_member263130]

Hello Luke,

First of all thanks a lot for your reply.

I already checked IMG activity documentation as well as help file but still has following questions:

1) How to record data as part of intial run so that when system go live it will have control limits already calculated.

2) We can define 4 Numeric Parameters and 2 whole number parameters and I guess depending on control chart type along with upper/lower specification defined for inspection characteristic, system will calculate warning as well as action limits. Please correct me if my understanding is wrong.

3) If we select SPC inspection as valuation mode in sampling procedure then system will consider these action/control limits for valuation and not specification limits specified in inspection characteristics. Please corrct me if my understanding is wrong.

4) System creates new control charts if no active chart is available but is it require to activate/release control charts once system creates it? There are transactions available to list control charts (QGC1, QGC 2 and QGC3) where we can activate as well as close charts but do we have to activate charts once created by system or we can start recording and system create as well as release control charts.

You may find some of my questions basic but I am not pro in SPC so it would be great if you can help me in clearing my doubts.

Thanks in advance.

Best regards,

Devang