Gu examines all aspects of the process in detail, from the source of the material to its processing. He looks for accurate, complete documentation and stresses the importance of quality control testing. He also focuses on sanitation, correct equipment usage and ensures that procedures for labeling and storing materials are adhered to.

FDA auditor Zi-qiang Gu is an extremely detailed and thorough auditor who focuses heavily on completeness, accuracy and adherence to manufacturing instructions, as well as impurity checks. He pays special attention to raw material inventory records, equipment cleanliness & usage, material sourcing, and material flow in the processing area. He also seems to place heavy emphasis on completeness of investigations carried out into failed and out of trend lots.