Defects and opportunities

Do you do create the metal components or are they purchased parts?

To avoid gamesmanship we have adopted the following as our opportunity count.
 
Three times the bill of material. This is a standrard and we maintain consistency which is what really counts.
 
 

GRG,
The old formula was parts plus connections. That meant you got one count for picking the correct part and another opportunity for each connection i.e. solder connection, screw, nail, etc.
You need to use the generalized rules with some degree of caution. They tend to overlook indigenous processes that may be an issue. The up side is to have a serious effect on your DPMO calulation by moving the denominator (opportunity count) you have to have a pretty significant change in the number of opportunities.
Good luck

There are valid reasons for reducing part counts, such as improved reliability, but opportunities should not be arbitrarily reduced to improve DPMO score. 
I agree that you must create a set of ground rules and stick to them.  Changing opportunities should only be allowed when there is an ACTUAL change to the process, such as redesign to reduce components.

GRG,
From your customers standpoint the count of 1 makes sense – as much as using DPMO makes sense in that situation. They are not concerned with your manufacturing opportunities. Each unit is an opportunity to supply a good part or a defective (not defects) part.
The count you are refering to (383) would be something that would make sense internally if your product was being compared with dissimilar products. The operation count is a way of off setting the effects of complexity between various products i.e. if you want to evaluate the performance difference between a sector making light bulbs, another making loans and another making aircraft engines.
As far as improvement projects on the line it would make more sense to run dpu. If you play with the opportunity counts and Sigma you will find they are pretty insensitive so it is difficult to make them move much. dpu sensitive enough to measure the effects of improvements you are making.
Just my opinion.
Good luck.

You should  not ignore  the  Root-Causation”.

For a supplied part, you get one opportunity. It’s right or it’s not.What PPM level do you need to achieve?

What is your current performance and how complex is the product?

Omashi Hibachi,
Are reading what you post? The post is around the measurement of the defect level. Nobody is talking about causation.
This must be Marlon Brando morphed into some new level of cosmic unconciousness.
Lebowski

GRG,
What are the possible consequences for not meeting the DPM requirement?

Is there a penality clause in your contract?
Is it a comparison between you and other suppliers that supply the same or similar complicated parts?
Is it a goal to be met with no particular consequences except in the case of being so much higher than everybody else the customer starts looking for another supplier?
How is the customer finding the defects they are reporting to you?

Receipt inspection?  If so, make your shipping inspection at least as rigorous as their receipt inspection.
During assembly?  If so, is there a way for you to do a test fitup prior to shopping the part?
You talk a lot about holes (threaded and non-threaded) being issues.  Can you test fit the fastener that will be used in that hole prior to shipping to test for fit and alignment?
You need to take the possible consequences of failure to meet the DPM requirement into account and decide how much inspection money you are willing to spend to avoid the customer finding defects.
Regards,
Jim Shelor

Achieving the target PPM while reducing inspections ought to be fairly straghtforward.

In the automotive industry, the PPM standard is for each unit you supply to the customer. As previously stated you had 1 opportunity to supply a good part and you failed.For internal PPM calc, I have had many discussions, again as mentioned previously pick a standard way that makes sense to your organisation and the level of detail you require, and stick to it across the board.