Automatic calculation of sample size

[vivek_varun2]

Hi all,

There is a requirement in my current project ,that  for packaging goods  when they procure suppose 1000 piece from vendor, for calculating sample they  use the formula as square root of n+1. where N is  GRN quantity.

How should I map this in system.

Thanks

Vivek

[vivek_varun2 · Accepted solution]

hi Nitin,

One more doubt I am getting is if, lot size and sample size relation we are maintaining in sampling scheme only then what is the use of sample drawing procedure...as system will pick the sample size as per sampling scheme only.

Thanks

Vivek

[nitin_jinagal · Accepted solution]

Hi Vivek,

In that case, you need to use sampling drawing procedure only. Sampling scheme should be used when sample size wrt lot size is fixed and known (As demonstrated in above example)

I stated before also that change the sampling type to fixed sample in Sampling procedure. Give sample size 1. This way system won't ask for sampling scheme and formula defined in SDP would be used for calculation.

In Sample drawing procedure, Make sure you enter Size factor 1 and TRUNC(SQRT(P2)+1) in the formula. Save it. 

• Assign this SDP to SP.
• In the inspection plan header, assign the SDP with inspection points 200.
• I assume all the MICs are active for Sampling procedure. While assigning these MICs to inspection plan, you would enter the SP to each MIC.

Now do the GR or reset any previous inspection lot, sample size would be calculated automatically as per the formula defined. Run a test case and observe the results and please revert.

ntn

[vivek_varun2 · Accepted solution]

Hi nitin,

Your point

Assign this SDP to SP.

I could not find any link in  sampling procedure to assign  SDP, please let me know how to do this.

Secondly I am attaching screen shots please check ,as I don't think  sample size calculated by system is according to the formula.

[nitin_jinagal · Accepted solution]

Hi,

Yes you are correct. SDP is never assigned to SP. I actually wanted to say Sample management. You have to set sample management in SP. I'm sorry for the typo error.

I'll run a test case and let you know what I get.

[nitin_jinagal · Accepted solution]

Hi Vivek,

You only need to change one thing and you will get desired results. i.e 32 sample size for the lot size of 1000.

In the formula, change P2 to P1 because P1 is for Lot size whereas P2 is for Container.

Other settings would remain same. I tested it and see below screen shots.

SDP:

SP:

Inspection plan header:

Inspection lot:

I'll write the points again and you should be able to get results this time.

1. In the Sampling drawing procedure:  Assign formula TRUNC(SQRT(P1)+1) & Size factor 1.
2. In the Sampling procedure, make similar setting as given above. Set sample management, Fixed sampling type and sample size.
3. In Inspection plan header, Assign 200 inspection points and SDP.
4. Make GR for 1000 qty, sample size would be calculated as 32.
5. Other than that, I have got sample size of 45 & 23 for lot sizes of  2000 and 500 respectively.

Pl check and revert.

ntn

[vivek_varun2 · Accepted solution]

Thanks Nitin,

Finally I got the correct solution .

Thanks a lot

Vivek

[nitin_jinagal · Accepted solution]

I'm glad to hear that

[vivek_varun2]

Any reply please

Thanks

Vivek Varun

[former_member184574]

Hi,

Formula you should mention as TRUNC(SQRT(P1)+1) where P1  is the lot quantity........coming to sample type in the sampling procedure use fixed sample only and check......

Thanks

Kumar

[vivek_varun2]

Hi kumar,

I think I am unable to explain my requirement.  I tried your suggestion, but what actually happening in that is , suppose I have given 10 PC in sampling procedure with fixed sample setting. system is creation sample size of 10  and number of sample is 32 for lot size 1000. My requirement is instead of  sample size 10 ,it should be 32 .

I don't think  by fixed sample this will come.

Thanks

Vivek Varun

[nitin_jinagal]

No. Fixed sample won't fix this.

If you need sample size of 32 for the lot size 1000, then you would need Sampling scheme for that. But earlier you said, this is not required.

Is there any pattern you are following for the sample size for different lot sizes?

ntn

[vivek_varun2]

Hi nitin,

can you please explain  how sampling scheme will work out. Can you  tell me steps which I need to  do for sampling scheme. I will check and let you know.

Thanks

Vivek Varun

[nitin_jinagal]

Hi Varun,

I'm not sure what you are looking for as you initially started with Sampling drawing procedure.

Anyways, sampling scheme works this way,

You can see that different sample sizes are maintained according to different lot sizes in the above example.

For the lot size upto 5, sample size is 3. Likewise, for the lot size upto 10, it is 4, for the lot size upto 20, it is 5.

In this way, you can define what the sample size would be for different lot size.

In your case, it would be upto lot size 1000, sample size 32.

You also define the Acceptance and Rejection number here (refer c1 and d1) where you set the highest figures for accepting & rejecting the inspection lot.

In sampling procedure, you define following type,

• Fixed sample- Fixed sample size irrespective of lot size.
• 100 % inspection- Nothing to explain in this I guess
• Sampling scheme- As described in above example
• Partial sample- You define %age of the lot size for calculating sample size.

Before following this, you need to know what exactly you are looking for!! We all are here to assist you, but you need to know what is required.

ntn

[vivek_varun2]

Hi nitin,

Its correct that I have started with sampling drawing procedure, but actually  my issue is system should calculate the sample size as per formula, and not fixed sample size. This scenario is new for me, so I am doing hit and trial. I tried with sample drawing  procedure and sampling scheme also as u have explained ,but my question is ,there is not any fixed lot size which client is procuring all time.so how many line items I will maintain in  sampling scheme.

What I was expecting was ...just by maintaining  formula in sample drawing procedure and assigning that in inspection plan system will calculate sample size according to that .

But now my issue is only the word above in bold.

Thanks

Vivek Varun

[vivek_varun2]

Any reply please,

I have given sampling drawing procedure in inspection plan header. but system is not calculating sample size according to that.

Thanks & Regards

Vivek Varun

[nitin_jinagal]

Hi,

I never actually worked with Sampling drawing procedure but I see the many help files & few discussions on this. Have you gone through them and made relevant settings?

I think that might be useful for you.

ntn

[former_member620323]

Hi,

1. In Sampling Drawing Procedure, Use FORMULA = TRUNC(SQRT(P2)+1) for calculating Physical Sample in Primary Samples Tab.

2. Assign this SDP in Inspection Plan Header.

3. Create Sampling Procedure with Sample Management

4. Assign this Procedure to MIC in Inspection Plan.

Please do setting & test..

[vivek_varun2]

Hi Rahul,

Thanks for the reply. I did same thing. I have created sampling drawing procedure with formula. created sampling procedure with  tick mark  sample management.assigned the sample drawing procedure in inspection plan .

But in sampling procedure system is asking sampling scheme. and when I give sample scheme in inspection lot system is showing the sample size same as what i maintain in sampling scheme. system is not considering the formula.

That is my problem.

Is there any thing which I missed or some thing where I  did wrong,I want to know that only. that is why I want full step by step procedure.

Thanks

Vivek Varun

[former_member620323]

In Sampling Procedure:

Check you have selected Sample Management.

In Sampling Drawing Procedure:

Only Enter Size factor: 1

& in a/c to formula ; TRUNC(SQRT(P2)+1)

[nitin_jinagal]

Hi,

I can figure one thing from your statement.

But in sampling procedure system is asking sampling scheme. and when I give sample scheme in inspection lot system is showing the sample size same as what i maintain in sampling scheme. system is not considering the formula.

That is my problem.

You must have chosen Sampling scheme in 'Sampling type' during creation of Sampling procedure.

Try with fixed sample. This way system wouldn't ask you to enter sampling scheme.

ntn

[vivek_varun2]

Hi Nitin,

thanks for the reply, if I use fixed sample in sampling procedure then system will ask for sample size( which is mandatory). and after giving sample size in sampling procedure system will always pick the fixed value in sample size...that means formula is not used.

Thanks

Vivek Varun

[vivek_varun2]

Hi Rahul,

What we should  give in sample type in sampling procedure

Thanks

Vivek Varun

[former_member184574]

Hi,

Check the below threads...They may help you out...

Thanks

Kumar

[vivek_varun2]

I have already tried this.... but its not solving my issue.

Can you give step by step procedure to achieve this scenario?

Thanks & Regards

Vivek Varun