Minor failure         NF

- Are mistakes which influence the expected usability of the product for the intended use only slightly.

- Doesn’t influence directly the normal-critical customer in the sales and leads to no complaints.

-.Awards the product a unclean and unskilful impression.

- The producer has to point out to this minor failure and has to provide for their elimination.
 

Principal fault        HF

- Are mistakes which influence the expected usability of the product for the intended use

 - Makes the product hardly to sale and leads with a normal-critical customer probably to complaints, prize reductions, credits or returns.

 

Critical defect        KF

- Are those through which the product gets unqualified for the intended use or becomes unsalable because it is damaged,   the function isn’t guaranteed or determining   processing defects are existent. 

- By the use of the product (material) leads to too high costs, because a before incalculable effort is necessary (additional consumption, aftercare, etc.)

- Which leads to a 2-nd choice production or committee.