Quality PPM (parts per million) Tracking - Stats for our Management Review Meeting

LexieB · Dec 18, 2009

Hello,

I am working on putting together some stats for our Management Review, and am a little stuck at figuring out the QPPM. I know the equation, and I can get a number (which is over our 500 goal).

My question is: What do ya'll include when calculating your internal QPPM?

I have:
1. Customer Returns
2. Customer Complaints (bad part repaired onsite or used as is)
3. Internal non conforming product records

Question #2: Would I be better off separating these somehow?

Question #3: Do you include minor product rejects? (ie - 10 screws rejected for 1000 made, but screws aren't anywhere near your only product and count against overall QPPM)

Note, I am keeping rejects caused by vendors separate.

Thanks in advance!!

Jim Wynne · Dec 18, 2009

Re: Quality PPM (parts per million) tracking

Any particular reason for using PPM? Are you dealing with millions of issues?

Umang Vidyarthi · Dec 18, 2009

Re: Quality PPM (parts per million) tracking

LexieB said:
Hello,

I am working on putting together some stats for our Management Review, and am a little stuck at figuring out the QPPM. I know the equation, and I can get a number (which is over our 500 goal).

My question is: What do ya'll include when calculating your internal QPPM?

I have:
1. Customer Returns
2. Customer Complaints (bad part repaired onsite or used as is)
3. Internal non conforming product records

Question #2: Would I be better off separating these somehow?

Question #3: Do you include minor product rejects? (ie - 10 screws rejected for 1000 made, but screws aren't anywhere near your only product and count against overall QPPM)

Note, I am keeping rejects caused by vendors separate.

Thanks in advance!!

Q 1&2: Yes, we maintain separate PPM for each customer as well as for internal NCs.

Q 3: We do include all rejects, major or minor to get the true picture, which is the basic purpose of taking QPPM.

It does not matter where you keep your rejects, as long as they are accounted for and included in the records.

Hope this helps

Umang

brahmaiah · Dec 19, 2009

Re: Quality PPM (parts per million) tracking

LexieB said:
Hello,

I am working on putting together some stats for our Management Review, and am a little stuck at figuring out the QPPM. I know the equation, and I can get a number (which is over our 500 goal).

My question is: What do ya'll include when calculating your internal QPPM?

I have:
1. Customer Returns
2. Customer Complaints (bad part repaired onsite or used as is)
3. Internal non conforming product records

Question #2: Would I be better off separating these somehow?

Question #3: Do you include minor product rejects? (ie - 10 screws rejected for 1000 made, but screws aren't anywhere near your only product and count against overall QPPM)

Note, I am keeping rejects caused by vendors separate.

Thanks in advance!!

Theoritically all three should be included in your PPM calculation.But it is practically immpossible to do it because customer returns , rejactions and field failures will not be available at the time of PPM calculation.They will be known long after the time of your monthly PPM calculations.But if you do your PPM calculations once in a year it is possible to include all three inputs in the calculations.
V.J.Brahmaiah

DrM2u · Dec 19, 2009

Re: Quality PPM (parts per million) tracking

LexieB said:
Hello,

I am working on putting together some stats for our Management Review, and am a little stuck at figuring out the QPPM. I know the equation, and I can get a number (which is over our 500 goal).

My question is: What do ya'll include when calculating your internal QPPM?

I have:
1. Customer Returns
2. Customer Complaints (bad part repaired onsite or used as is)
3. Internal non conforming product records

It depends from organization to organization if the PPM is a good indicator. Sometimes you'll have to consider other metrics, like the value of internal and external failures, the value of internal and external delays, the value of obsolete product, etc.. This ties more directly to the company's bottom line. After all you are in business to make money not widgets!

LexieB said:
Question #2: Would I be better off separating these somehow?

I suggest to keep customer returns separate from internal failures. One reason is that you might use separate indicators for each (not necesarily PPM). For example, it is not practical to calculate PPM when a company has a large variation in product sizes, value, quantities, etc. A product with orders of 1000 pc/year can have a high PPM from one failures while a product ordered in millions can have a low PPM even if the number of failures is 100. In such cases you would be better off looking at the dollar value of the failures and the reasons (Pareto reasons by value and by occurence to identify the major culprits). Another reason to keep them separate is to compare if the external failures and larger (big problem!) or not than the internal failures; this is an indicator of how effective internal controls are. Last but not least, customer complains are not realy a part of the PPM calculations since you can get returns without formal complaints.

LexieB said:
Question #3: Do you include minor product rejects? (ie - 10 screws rejected for 1000 made, but screws aren't anywhere near your only product and count against overall QPPM)

Think of the value of the data. Is it valuable to have this kind of detail or should you take a 'higher' or 'distant' look? Keep in mind that data collection and analysis costs resources (time, money, manpower, equipment, etc) and are wasteful if the benefits do not exceed those costs. I suggest to start looking from what consultants call the '10,000 miles in the air' then dive into details only when you need to better define problems or identify failures.

LexieB · Dec 21, 2009

Re: Quality PPM (parts per million) tracking

Jim Wynne said:
Any particular reason for using PPM? Are you dealing with millions of issues?

Our customer actually requires it. They require us to follow the same SPC, statistical methods, QPPM calculations as the big boys.

Jim Wynne · Dec 21, 2009

Re: Quality PPM (parts per million) tracking

LexieB said:
Our customer actually requires it. They require us to follow the same SPC, statistical methods, QPPM calculations as the big boys.

OK. That's the only good reason to use PPM when you're not dealing with millions of things. It's sort of like measuring the distance of your daily trip to work in light-years.

As you've probably seen from some of the responses so far, you need to be careful with categories and definitions. If you want to keep it as simple as possible, just count the number of things made vs. the number of saleable things. Simple yield, in other words.

LexieB · Dec 21, 2009

Re: Quality PPM (parts per million) tracking

DrM2u said:
It depends from organization to organization if the PPM is a good indicator. Sometimes you'll have to consider other metrics, like the value of internal and external failures, the value of internal and external delays, the value of obsolete product, etc.. This ties more directly to the company's bottom line. After all you are in business to make money not widgets!

I suggest to keep customer returns separate from internal failures. One reason is that you might use separate indicators for each (not necesarily PPM). For example, it is not practical to calculate PPM when a company has a large variation in product sizes, value, quantities, etc. A product with orders of 1000 pc/year can have a high PPM from one failures while a product ordered in millions can have a low PPM even if the number of failures is 100. In such cases you would be better off looking at the dollar value of the failures and the reasons (Pareto reasons by value and by occurence to identify the major culprits). Another reason to keep them separate is to compare if the external failures and larger (big problem!) or not than the internal failures; this is an indicator of how effective internal controls are. Last but not least, customer complains are not realy a part of the PPM calculations since you can get returns without formal complaints.

Think of the value of the data. Is it valuable to have this kind of detail or should you take a 'higher' or 'distant' look? Keep in mind that data collection and analysis costs resources (time, money, manpower, equipment, etc) and are wasteful if the benefits do not exceed those costs. I suggest to start looking from what consultants call the '10,000 miles in the air' then dive into details only when you need to better define problems or identify failures.

This is very helpful.

So basically I can sort it out by common sense? (You never know... hehe)

I have one more question: Should successfully reworked product be included? Someone told me that it shouldn't, but based on the fact that it was rejected in the first place and extra time had to be spent to fix, I would want to could it.

DrM2u · Dec 21, 2009

Re: Quality PPM (parts per million) tracking

LexieB said:
This is very helpful.

So basically I can sort it out by common sense? (You never know... hehe)

I have one more question: Should successfully reworked product be included? Someone told me that it shouldn't, but based on the fact that it was rejected in the first place and extra time had to be spent to fix, I would want to could it.

I would say no for reworked product, just to keep things simple. The main and most relevant indicator is the 'first-time-through', unless you want to monitor how well you can reqork product.

With regards to the customer's requirements, first try to identify if the requirement for PPM is a formal one or just something that an inexperience SQE asks for. Ask for their supplier quality manual (if they have one) and see if the specific requirement is there. If it is, ask for a formal waiver on the requirement. If it isn't then you are facing the task to 'educate' your SQE. Either way, be prepared to explain why measuring PPM is not relevant and useful for the organization. :bonk:

As far as using the 'big boys' for an example, you can remind your customer about their financial situation and how well they are doing (specifically GM and Chrysler).

I almost forgot ... if you use the value of failures as an indicator (instead of the number of instances) then you can still use PPM as a metric: Pennies Per Million $ sales. You can even take the Six-Sigma approach and use DPM (Dollars Per Million $ sales).

This way you can still make your customer happy that you are using PPM or DPM. :agree1:

What they don't know won't hurt ... you. :lmao:

Quality PPM (parts per million) Tracking - Stats for our Management Review Meeting

LexieB

Jim Wynne

Umang Vidyarthi

brahmaiah

DrM2u

LexieB

Jim Wynne

LexieB

DrM2u

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