The correct answer is: Abnormal waste.
Abnormal waste is waste that is not expected to occur in the normal course of production. It is caused by factors such as accidents, equipment failure, or operator error. Abnormal waste can be reduced or eliminated by improving quality control, implementing preventive maintenance, and providing proper training to operators.
Normal waste is waste that is expected to occur in the normal course of production. It is caused by factors such as the inherent nature of the material being processed, the design of the production process, and the efficiency of the production process. Normal waste can be reduced but not eliminated.
Both abnormal waste and normal waste do not form part of production. However, abnormal waste is more costly than normal waste because it is caused by preventable factors.