Calculating PPM for a Supplier on a Specific Defect - Excel .xls Spreadsheet Wanted

[jkittle]

My boss wants me to calculate the PPM for a supplier on a specific defect.

Does anyone have an Excel spread sheet to do this?

[Jim Wynne]

Using a spreadsheet seems like overkill; in its simplest (and most misleading) form, PPM is calculated as a proportion of a small population projected onto a larger one. If you have a 1000-piece population and 10 defectives, 1% of the population is "bad." 1% of 1,000,000 is 10,000. So the formula would be 10/1000*1,000,000 =10,000 PPM.

Note that if you don't have evidence to support the contention that the defect rate will remain constant through the production of 1mm pieces, there's no good reason to use PPM as a yardstick.

[Canonman23]

I have an excel spreadsheet that we use for DPMO.......but the previous post pretty much sums it up and very easily. Just let me know if you'd like a copy of the spreadhseet .

Neil

[jkittle]

Thank Jim ans Neil.

I would be interested in your DPMO sheet though.


Jerry

[Canonman23]

This is an example I have. I've scaled it down and added a little note for comments. Let me know if have any questions.
Neil

[Jim Wynne]

In Reply to Parent Post by Canonman23

This is an example I have. I've scaled it down and added a little note for comments. Let me know if have any questions.
Neil

Can you explain your algorithm? For example, you show "Monthly hardware number of completions"= 88, and "Quantity of fallouts" = 6, and then in your formula the two are added together. Aren't the number of fallouts already included in the 88 "completions"? In other words, are you saying that there were 88 units and 6 of them failed, or are you saying that there were 94 units total?

If we take the former as correct (6 of 88 failed) and there are 44 opportunities per unit (88 * 44), this means that there were 3872 opportunities and 6 actual failures. DPMO should be 6/3872*1000000=1550 (rounded) rather than the 1451 you give. Or did I miss the bus?

[Canonman23]

My mistake.......(thats what I get for multi-tasking!). It is :
Rejects*1,000,000/(#Lots Produced*OFD)
OFD = Opportunity For Defects [in this case it was 44]

Thanks for catching that and the real number is rounded to 1550. We actually produce several product lines and for right or wrong they all get averaged together so the formula gets a little muddy (not that I'm making excuses)
Neil

[Jim Wynne]

No problem--I just wanted to make sure it was clear for the OP, and that it wasn't me