Product failure
Ben Osburn 14981
7 Posts
How many times can a product feature fail, before an audit is done? I work for a place that's does not really have processes documentation for many things. We had a DPU of 33/52=63% on a product feature recently. I'm wondering if I should have the product audited before it's shipped again and THEN do an audit if its noncompliant, or if I should audit the failure mode now DURING the process.

Is there any sort of numeric guideline regarding how may times a product feature can fail before a product audit is done? 
4 Replies
I am not aware of a general industry standard practice for such determination (numerical guideline to trigger investigation).

Products defects in some industries are very tolerant, so defects rarely  trigger any action.  e.g.
                An MDT failure in a Circuit Assemble shop.  (note: MDT is a pretest before final inspection – failures are just scrapped. No action unless exceed $ point).
                Graded product (e.g.  Food – nice fruits go to produce aisle, bruised  fruits go to juicing).

In some  industries, a feature can be labeled as ’critical’, and if a defect is encountered, a production line stoppage will occur with an 8D style investigation initiated and addressed before restart.

If provide more details of the type of feature, product, and industry, maybe can give recommendation. 
Ben Osburn 14981
7 Posts
Hey James,

So we don't really have an FMEA for any product(sadly) but this feature on our product is really important. We make our product in batches, so this particular batch had a DPU of 63%, so its's pretty severe. I just want to make sure the product is made correctly the next time
I am sure we can provide some suggestions.

How does operators know how to make the product?   
     -  Does their company provide drawings or specifications?
     -  Does customer provide drawings or specifications?
     -  Is it made to a generally available industry standard?
     -  Is it made base on handed down information from/during training?
     -  other? explain.

How does job orders make it to production (to the operators)?
     - Use of a Job traveler
     - Kanban system
     - Copy of PO from customer sent to operators
     - Operation software send message (ERP, MRP, or such)
     - Continuity production (they make the same product each day, so need to to tell them what or how much to make each day)
     - other?
Ben, What is the risk here? Is there a history of tolerated failures? What does it cost to fix it later? Defects have causes, some are all about stopping escapes, some are about prevention, some causes may not be preventable. How important is (are) the feature(s) that fail? If you seek a numeric guide, I would look at cost of quality: What do you spend on prevention, what is the cost of auditing, what is the cost of rework before you ship, what is the cost if the defect is found by the customer? Are you spending enough on prevention? See Principles of Quality Cost and/or The Executive Guide To Understanding And Implementing Quality Cost  .