sample drawing procedure

[raju_123]

Dear gurus, in manufacture of steel pipe, we check the pipe dimension like length, diameter for every 10 pipes produced, 1 pipe will be tested for mechanical properties for every 500 pipes and chemical analysis will be done for 1 for every 1000 pipes produced.i thought of creating one insp plan with 3 operations like dimensional verification, mech verification, chemical testing. reg sample procedure I thought of assigning fixed sample 1 for 10, 1 for 500, 1 for 1000 for the characteristics of its operations. is there any better way doing this. can we use sample drawing procedure here. if we assign sample drawing procedure, then it will be applicable for all 3 opeartions which is not required. could you please advise how to use sample drawing procedure in this case. where exactly sample drawing procedure is used. please advise.

[Former Member · Accepted solution]

Are you willing to use Sample managment for inprocess inspection ?

If not then do not use SDP .

Best way is to ensure all this through sampling procedure with amy be fixed type of sampling type or may be % type of sampling.

[former_member42743]

Part of this depends on how many pipes you typically make in run.

Is your minimum order size at least 1000 pipes since you do chemical analysis every 1000?

A fixed sample size is typically good where your order size is consistent or you just do a single sample size of 1.  If you always do runs of 1000, then you can do it just as you indicated, using a fixed sampling procedure.

You typically only use sample drawing procedures when you use physical samples.

It sounds like a better fit for you might be a sampling procedure using a sampling scheme.

In the sampling scheme you can define sample sizes based on the expected run size.  This works better when your production runs vary, i.e. 1000 pipes one day, but another product type might be runs of 5000.  You'll still need the same number of sampling procedures.   Just use a sampling scheme with them.

FF

[raju_123]

Thank You FF.

So incase we have dimensional inspection and physical sampling inspection, do we need to create 2 seperate insp plans one for dimensional insp and other for physical sample? Generally how it should be handled in manufacturing industry. please advise.

[former_member42743]

You can still use physical samples with your dimensional inspection.  (I've seen plants actually afix the sample label to the item, you know...kind of like the "inspected by inspector number 6".)  And you don't need to print out labels.   

I'd be consistent and use physical samples across the board for a given material. But I'm not sure you really need to use them.  Seems like a lot of extra work for pipe inspection.  It's primary use is to allow the tracking of samples in the lab where multiple sample are collected, maybe pooled together, maybe some are sent off-site, maybe some go to one section of the lab while others go to different sections of the lab and where companies keep retained samples and reserve samples of the product.  It also allows for sample sheet to be printed which can be used for pulling the samples and showing custody of the samples.  It's used mostly in Pharma and some chemical firms.

FF