In any industry, defect and defectives are the words being used interchangeably though their
meanings are not so similar. Defect is the non-conformity or we can say it is the imperfection in
a unit or the deviation from a specification or standard. For e.g. A scratch on door panel of a car
is a defect as it is the imperfection but this small scratch may not lead to the non-acceptance of
car by the customer. So, a defect is a nonconformance on any one of the many possible quality
characteristics of a unit that may cause customer dissatisfaction. A defect doesn’t essentially
make a unit defective. For e.g. a pen can have a scratch on its outer body (defect) and still be
used to write (not defective). However, if a customer wants a scratch-free pen, then that
scratched pen could be considered defective.
If the functionality of a unit hampers by one or more defects, and unit fails to meet the
required criteria or customer expectations, then this unit, containing 1 or more defects is
defective. So, defective is the non-conforming unit & may contains one or millions of defects.
For e.g. If there are 14 scratches (defect no. 1), 5 dents (defect no. 2), rust (defect no.3) then
customer will not accept the car and hence, the car becomes defective.
In Lean Six Sigma, the term DPMO (defects per million opportunities) is used to measure the
performance of a process. You can note that this is the measurement of defects and not
defectives. If in a product 10 defects can be there then the opportunities are 10 and if only 1
defect is present then it is 1 defect per 10 opportunities. Moving forward, if there are 20
defects in 100 products (which have 10 defect opportunities per product), then Defect per
opportunity will not be 20/100, instead it will be 20/(100*10) = 20/1000= 0.02 DPO & Defect
per million opportunity will be 0.02*1,000,000 = 200,000 DPMO