Defects and defectives

Customers expect products and services to meet their specifications. When they don't, a defect or defective is present.

For example, a candle's wick should be long enough to light; a waiter should greet his table within 3 minutes of seating.

·    A defect is any departure from these specifications. A defect does not necessarily mean that the product or service cannot be used, just that it wasn't as intended. For example, if a candle wick is not long enough, the candle cannot be used; but if a waiter greets his table after 5 minutes, the customer can still order and enjoy a meal even though the greeting did not meet expectations.

·    A defective is when the whole product or service is considered unacceptable. Each product unit or service experience is either considered defective or not - there are only two choices.

A defective unit will contain 1 or more defects. New cars may have several defects, some of which may not even be noticed by the customer, but if the car contains a measured and reported defect, the car (or part of the car) may be considered defective.

Consider the loan application process. In this case, the processing department is the customer. You want to know how many defects they see. Your form has 36 entries. You sample 50 forms to estimate the defect rate. One application has 7 incorrect entries - there are 7 defects present on this form. Another application has 4 incorrect entries - there are 4 defects present on this form. Overall, 18 forms have at least one defect, so 18 forms are defective out of 50. Also, as we counted 62 total defects per 1800 opportunities (36 opportunities per form * 50 forms).