Rule for Automatic Valuation Inspection Lot UD

[Jhonc]

An attributive inspection is an acceptance sampling inspection. This means that the number of nonconforming units or defects in a sample determines the acceptability of the Inspection Lot, we think not for inspection characteristic only.

We know, that SAP can doing “Automatic Valuation” for the Inspection Characteristic based on ISO 2859. But could SAP do “Automatic Valuation” in Usage Decision for inspection Lot based on ISO 2859?

Suppose that, if all inspection characteristics have acceptance number of nonconforming units max = 2 in ISO 2859, and the inspection lot have 3 Inspection Characteristics.
There are 1 sampling nonconforming unit in IC “A”, 1 sampling nonconforming units in IC “B”, and 1 sampling nonconforming units in IC “C” .
Because of the acceptance number of nonconforming units max= 2, so all the Inspection Characteristics in that inspection Lot ( IC “A”, IC “B”, and IC “C“) are automatic valuated as ” Accept “.

In Automatic Usage Decisions for inspection Lot , SAP give valuation “ Accept”, because all Inspection Characteristic is Accept, but we need that inspection Lot is Rejected because the total number of nonconforming units in that inspection Lot are 3, so that exceed the acceptance number max = 2. How come SAP can have different way to valuate the inspection lot ( not based on the number of nonconforming unit ? )Or Perharps there are solution for this problem and am I wrong?

[Craig]

I'd have to really look at this in depth which I think is beyond this forum but I think a solution could be found.

I'm thinking maybe a couple of calculated characteristics. One would be the sum of the non-conforming units. One would be the sum of the number of units. You would then probably have to create a custom UD valuation rule that looks at these two characteristics and determines the pass/fail passed on the ISO procedure you want to use.

The problem I see is that in your scenario, what if the same item resulted in the one reject for each of the three characteristics? In which case you have only one defective item in your lot which should result in a pass. You are assuming in your scenario that three different items resulted in the three recorded failed characteristics. The more characteristics you have, the more item you have, the higher the number of defects you have, the harder this becomes to determine.

The easiest way would be to have one characteristic called Defective Units. Set the valuation of this based on your ISO spec. Someone determines the actual number of bad units, (not necessarily recorded defects since one unit can result in multiple defects being recorded).

The UD is than primarily based on that one characteristic cause you make sure all the other charac. pass regardless of number of defects recorded.

Craig

[Jhonc]

Hi Craig,

Thanks for deeply understand about my point.
This problem is raised by the user, and I think that solusion is tricky, but smart.
The users are having rule based on ISO that calculated the nonconforming units or defect unit from the total of the inspection characteristic in one inspection lot ( Regardless the weighting of each inspection characteristics, minor, major or critical ). They want SAP can valuate the inspection lot by doing usage decision based on their rule.

But the fact is SAP can doing automatic valuation with sampling procedure based on each inspection characteristic, and it's not based on the inspection lot, right ?

[Craig]

Hi Craig,

But the fact is SAP can doing automatic valuation with sampling procedure based on each inspection characteristic, and it's not based on the inspection lot, right ?

In SAP there are two types of evaluation. The evalution of the characteristic and the evaluation of the lot. They are independent of each other.

The characteristics are evaluated. These can be evaluated in a number of ways. A simple pass/fail, based on number of defective units, based on a sampling scheme, (usually ISO based), SPC, Classed recording, etc.....

The evaluation of an inspection lot is fairly simple. If you want to use automatic Ud, than if ALL the characteristics pass, the lot passes. Otherwise someone has to actually LOOK at the lot and determine if they want to pass or reject the lot. That's it for a UD.

So the key is determining which characteristics you want to use to determine the fate of the lot. Those that are unimportant, you set up so that they pass all the time. So you in the example I gave you, I was not saying that the first characteristics are unimportant, I just used them as input to a final calculated characteristic. That final characteristisc than is the one that winds up determing the evaluation of the lot. We are in essence kind of tricking the system if you want.

Craig