Definition of niggling for English Language Learners. : causing you to feel a slight pain or to be worried or annoyed for a long time.
What is PPAP? The Production Part Approval Process (PPAP) is a standardized process in the automotive and aerospace industries that helps manufacturers and suppliers communicate and approve production designs and processes before, during, and after manufacture.
The PPAP manual is the ultimate resource for those in automotive supplier quality management. The manual contains the PPAP checklist which includes all the requirements, called elements, for a complete PPAP package. The checklists identify different PPAP levels (from 1 to 5). For those in the automotive industry, there are 18 possible elements that must be checked off.