 1) Thickness of the base got undersized due to excess abrasion.|2) The fitting operator did not ensured the thickness of the part during polishing of the base.|3) Operator was not aware of what rework need to be exactly done to the part and he polished the part without measuring the thickness.|4) Due to miss communication between the operator and the supervisor the operator polished the surface of all the parts instead of reworking the dent in one part.