Industrial scales and MSA (IATF 16949 requirement 7.1.5.1.1)

[Ninja]

Since ship qty is determined using the scale, it's hard to leave it out totally (possible, just hard).
I would "weasel" my way around the MSA simply by having an email conversation with the customer (someone I conversed with frequently) about how we ship...preferably as an aside in a more important topic chain...

The conversation would be low key, and include that we use the scale, but that it was pointless to run MSA for such an everyday thing.
As soon as they email "sounds good" or "we understand" or "works for us" or such...you've got your butt covered.

 

[Jim Wynne]

Since ship qty is determined using the scale, it's hard to leave it out totally (possible, just hard).
I would "weasel" my way around the MSA simply by having an email conversation with the customer (someone I conversed with frequently) about how we ship...preferably as an aside in a more important topic chain...

The conversation would be low key, and include that we use the scale, but that it was pointless to run MSA for such an everyday thing.
As soon as they email "sounds good" or "we understand" or "works for us" or such...you've got your butt covered.

This assumes that there is customer demand in the OP's case, which isn't in evidence at this point. In all cases, when a customer is asking for something unreasonable, it is good to try to talk them out of it, but in my experience it's hard to find anyone who's willing to make a decision. A possible rationale for leaving things off of the control plan is to use the PFMEA as ammunition. If the weighing/counting of the material was considered in the PFMEA process and it was determined that risks were low or negligible, there's no reason for it to be on the control plan.

 

[Ninja]

This assumes that there is customer demand in the OP's case, which isn't in evidence at this point.

Fair enough. I've only ever made Control Plans for single customer products...I did make the assumption that this, too, was a single customer product which may not be the case.

 

[Mikey324]

In my opinion, other than being non-value added, its also a safety concern. We have scales up to 50,000 lbs at our plant. we do not do MSA studies for them. That would be an excessive amount of overhead crane lifts with no real benefit at the end of the day. Plus, lifting material on an off the scale with 3 operators, 10 "samples", and 3 trials would completely shut down that end of our facility. Unreasonable and unnecessary IMO.

 

[joekirk]

Doing an MSA on a scale used for counting is not a bad idea. You could identify unwanted variation such as procedure being followed properly, not taring out container properly, etc... I have had several clients have pretty substantial issues due to improperly using scales when counting parts. One particular client found that they were actually giving away 3% more parts than they were getting paid for...

 

[Jim Wynne]

Doing an MSA on a scale used for counting is not a bad idea. You could identify unwanted variation such as procedure being followed properly, not taring out container properly, etc... I have had several clients have pretty substantial issues due to improperly using scales when counting parts. One particular client found that they were actually giving away 3% more parts than they were getting paid for...

You can just train and verify competency without doing MSA.

 

[Jack Chiew]

Hi Chiheb G
I am an IATF auditor. MSA is required for your weighing machines, unfortunately. There are 2 possibilities that they can be exempted:-
1) If your relevant customers give written approval that MSA is not required
2) it is for secondary measurement. Example, for some very small parts, counting by hand is the primarily method, but you want to use the weighing balance to do a quick cross-check.
In fact weighing machines can be highly sensitive. In some countries, even legal requirement is involved. Example, weigh-bridge calibration in many countries are only to be calibrated by government metrological labs.
Anyway, calibration and MSA have same purpose but different scope. Full MSA include: repeatability, reproducibility, bias, stability and linearity. They combined to tell how reliable is the measuring system. Calibration measures the bias and some degree of lineality. If you are not dealing with North American customers, GR&R is normally acceptable in place of MSA. GR&R = repeatability + reproducability only. From GR&R results, you will see some indications of where the problem lies. If the error is high on EV, equipment is having problem. If AV is high, there are problems with the appraisers (people), method or measuring conditions. You should read up the MSA reference manual by AIAG. But there is something new coming form IATF, as we speak. Hope to update this at a later date when i have gone through the lessons.

 

[Marc]

1) If your relevant customers give written approval that MSA is not required

Just to be clear, where (what document) is this stated?

As an FYI to others, there are editable Gage R&R forms here: Some Gage R&R forms

 

[Jack Chiew]

Hi Chiheb G,
I am an IATF auditor, just joining the group.
Weighing scales require calibration and MSA. You can be exempted only under 2 circumstances:
1) customer gives you a written waiver
2) it is only use to compare with a primary verification. Example, some small parts use hand-counting, but later uses a weighing scale to confirm before packing
Weighing scale may involved legal requirement. Example, weigh bridge in many countries can only be calibrated by government metrological labs.
There is a difference between MSA and calibration. Full MSA checks for repeatability, reproduceability, bias, stability and linearity. Calibration touches only on the bias and linearity. Calibration is all about the equipment, whereas MSA checks on both equipment and other factors e.g. appraisers, method, operating conditions etc. If you are not dealing with North American customers, GR&R normally suffice. GR&R is the repeatability and reproduceability. From the study results, you can know the problem area. If EV is high, it means the equipment is not OK. If AV is high, it means the other factors have problem e.g. appraisers, method, operating conditions etc. There is also the ndc value required in GR&R that says about the resolution of the readings. You can read up the AIAG reference manual on MSA. But as we speak, there are revisions taking place. I hope to update this later, when i have taken the lessons from IATF.
I attach a sample GR&R, which is found in a book i published. The book is for free download. Hope it is of help.

 

[Miner]

As an FYI to others, there are editable Gage R&R forms here: Some Gage R&R forms

Even more forms here.