What type of defect materially reduces the use of the unit or part for its intended purpose?

The classification of defects in a maintenance or production context is essential for understanding their impact on the functionality and performance of a unit or part. A major defect is one that materially reduces the unit's or part's effectiveness for its intended purpose. This means that the defect is significant enough to affect the performance, safety, or usability of the equipment.

For instance, if a component has a major defect, it may still function but could compromise the overall performance or safety standards that the equipment is supposed to meet. This can lead to operational inefficiencies or even hazardous situations, necessitating repairs or replacements before the unit can be safely and effectively used.

In comparison, critical defects are typically those that render the unit completely unusable, and while minor and negligible defects may result in some inconvenience, they do not significantly impair the intended function of the equipment. Understanding these classifications helps prioritize repairs and ensures that critical safety and operational standards are maintained.