Rejection PPM Calculation

By simple arithmetic.

Sounds like a homework problem.

If I had a hammer . . . .

In each instance, 1,000,000 (n_in - n_out)/n_in.

It's not how many get rejected, it's how many get returned that matters....

I prefer to analyze DPMO, and not PPM as PPM does not give any indication as to why the parts got rejected.

Maybe you could shoot up a flare, cause you're lost!

Create a new department called A1 and have them count all the rejected parts.

You asked: "How to calculate rejection PPM of Plant?"

The aggregate rejection rate, ie, of all the departments combined, ie, 'the plant', in the same manner as Tornado outlined above in #4.

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ps: If this is a homework problem (and a trivial one at that), I'm guessing you:

* aren't paying attention in class?

or

* are paying attention in class but have no knack for this sort of thing and so may wish to reconsider your major?

I'm not trying to be snarky. Really I'm not. I'm just thinking that if you've honestly tried to understand this stuff but just can't get a feel for it, you may wish to consider an alternative major; something more suited to your particular talents and abilities. No crime in that - the best software engineer I ever met bar none was a medical-school dropout. His dad wanted him to become a neurosurgeon but his true love was computer science. He eventually got his PhD in that.

"Another reason to ban anonymous posters. No way to track the lazy losers and differentiate them from real members.

"If even anonymous posters have to register, as I have been told, let them stand behind all their posts!"

My reply was in the context of your stated objections to anonymous posters, not posters posing homework questions, was it not? If you are equating 'lazy losers' with those posting homework questions, perhaps you should have made this equivalence clear? I am not a telepath, Lyn, in spite of my ex's insistence otherwise.

Well, I suppose we could say that there is a failure to communicate. Superficially it may look that way, anyway, but I think we both know that isn't the whole story.

I rather think I touched a nerve when I alluded to the fact that the behavior on this forum may prompt others to use anonymity as a preemptive defense. Would you agree that civil behavior on this forum is somewhat lacking? I mean, I've only been here a few days and even I can tell.

Not once in your post did you say anything at all about homework posts. Not once. The entire thrust of your post concerned anonymous posters generally. But in reply to my comment you suddenly switch horses mid-stream and now the context is homework questions specifically? Why would you do that when the context of my comment was perfectly clear - unless of course the subject is hitting a wee bit too close and so we bring out the diversionary tactics? Dead giveaway. So why are you so uncomfortable with the idea that we may be largely at fault where anonymous posters are concerned? Because it's true?

There was no failure to communicate, Lyn. We understand each other perfectly.

Sensitive PC answers has went....

"I've only been here a few days" says it all.

Instead of offering lessons in forum etiquette, you can always do everything in your power to answer the question offered by the Anonymous Poster.

Aside from suggesting that they change professions, what have you offered in the way of constructive help, except:

"you may wish to consider an alternative major"

" If this is a homework problem (and a trivial one at that), I'm guessing you:

* aren't paying attention in class?"

I'm guessing that if you knew that 1% is equal to 10,000 ppm, you'd be able to answer this question yourself.

Those sorts of rejection figures just wouldn't be acceptable in a Japanese manufacturing unit; these just don't make rejects.

I'm at home and can do some work on this. Homework you might say. I think I have read and answered your question correctly. No doubt soon to be advised by CR4 members if not. This is how I see it.

X1 has 10 rejects out of 10,000 they started with. Pro-rate this means they would make 10 dud ones for every 10,000 they take in, until they made a million, where there would be one thousand rejects. The same as saying 1,000 ppm in numbers.

X2 has 30 rejects out of 9,990 they started with. Pro-rate this means they would make 30 dud ones for every 9,990 they take in, until they made a million, where there would be 3 thousand and 3 rejects. The same as saying 3,003 ppm in numbers.

Y1 has 50 rejects out of 9,960 they started with. Pro-rate this means they would make 50 dud ones for every 9,910 they take in, until they made a million, where there would be 5 thousand and 20 rejects. The same as saying 5,020 ppm in numbers.

Finally (although not asked) the overall rate would 90 rejects in all from the original 10,000 which is 9,000 ppm.

I don't have any experience in mass production or sampling methods, but it sounds quite a lot to me.

Mathwise words: Quantity of Rejects times 1 million divided by quantity to start with = qty in ppm