calculation of sample size in Sample drawing procedure

[former_member184574]

Hi,

I have created a sampling drawing procedure with following parameters..

Primary Samples: Fixed number 5 and size factor 2

Pooled Samples : Fixed number 2 and size factor 2

Reserve samples : Fixed number 1, sample qty 100 g, sample unit G

For a raw material I have created a inspection plan and assigned above sampling drawing procedure and also made all the relevant master data settings...Now created Purchase Order for qty 500 KG , then made GR for the PO then inspection lot got generated and physical samples got generated as below....

Now I am ok with no of Reserve sample i.e.1 and sample size of 100 G.....everything fine in case of Reserve sample

Coming to No of Primary samples are 5, that is fine but how system calculated sample size as 80 G for each.....

Coming to No of Pooled samples are 2, that is fine but how system calculated sample size as 100 G for each.....

can any body explain how system calculates qty's of physical samples sizes....and also overall inspection lot sample size is 0.500 KG ..How this is calculated...plz explain.....

Thanks

Kumar

[Former Member · Accepted solution]

Hi K Kumar ,

Please check transaction QDV3( Sampling Procedure) and Sampling Scheme(QDV3),and check how many quantity is assigned in sampling scheme . which sampling scheme is used in sampling procedure. and you will get your answer regarding problem.

Regards,

Sameer

[former_member184574 · Accepted solution]

Hi Sameer,

Thanks for your reply.. I am not using sampling schemes...sampling procedures are fixed samples as explained to Mr. Manish...

My problem is not with no of physical samples ....issue with sample size of physical samples like 80 g of primary samples and 100 gms of pooled samples...how this sample size is calculated....

Thanks

Kumar

[former_member42743 · Accepted solution]

In the control indicators, have you marked any of the MIC's as destructive tests?  Also, have you assigned partial sample numbers to the MIC's in the inspection plan?

Craig

[former_member184574 · Accepted solution]

Hi Craig,

Thanks for your reply...I have checked in the control indicators for MIC's...They are not marked for destructive tests......and also there is no assignment of partial sample numbers to MIC's in the inspection plan.....

Inspection plan got two operations...first operation is assigned with two MIC's and both have sampling procedure of fixed with sample qty 5 and base sample qty 10 gm

Second operation is having two MIC's and both have sampling procedure of fixed with sample qty 1 and base sample qty 10 gm...

One more thing is sample drawing procedure used in the inspection plan is marked with indicator consider no of containers and while make the GR against Purchase Order no of containers are 4..........

Thanks

Kumar

[former_member42743 · Accepted solution]

Operation 1 determines your required quantity.

5 samples at 10 g apiece = 50g.

Since operation two doesn't use a separate partial sample number, it assumes you're using the same 50 g from operation 1 to cover operation 2.  If you had specified separate partial samples, then it would say you need 60g (50 +10).

So, you then said in the sample drawing procedure that you wanted 2 pooled samples with a size factor of 2.

50 * 2 = 100g

50 * 2 = 100g

Your total qty of pooled samples is 200 g.

You said in the sample drawing procedure to get the pooled samples from 5 primary samples.

So... 200g/5 = 40 g per primary sample.

But you also applied a size factor of 2 to the primary samples

So you get 40g * 2 = 80g per primary sample.

This help file should help you with this:

Determining the Physical-Sample Sizes - Sample Management (QM-IM-SM) - SAP Library

Craig

[former_member184574 · Accepted solution]

Hi Craig,

Thanks for your reply...All my issues resolved now....I am struggling to figure out this for the past two days.....Great help....where I went wrong is I am not aware of this partial sample feature...so I calculated initial sample size as 50+10 = 60 g.. from here everything went wrong........

Closing the thread and will do the testing with different combinations and will come back if any issues are there.....

Thanks again

Kumar

[former_member184536]

Hi K Kumar

Please check your sampling procedure assigned to characteristics and sampling qty, you will get you answer.

Manish

[former_member184574]

Hi,

Thanks for your reply......

My Inspection plan is having two operations.....

Operation 1 : two MIC's with both having sampling procedures as fixed sample size as 5 and  base sample qty as 10 grams

Operation 2 : two MIC's with both having sampling procedures as fixed sample size as 1 and base sample qty as 10 grams

Still not able to figure out how primary samples size is calculated as 80 g...

Thanks

Kumar