This document discusses process validation for pharmaceutical drug products. It defines process validation as documented evidence that a process can reproducibly produce a product meeting its specifications. Process validation is required by cGMP regulations and must be done before market approval. Traditional prospective validation establishes evidence before implementation, while continuous process verification monitors current production. Validation covers facilities, equipment, methods, staff training, and includes design space verification. The validation scheme submitted to regulators includes the manufacturing process description, in-process controls, acceptance criteria and reports.