As identified in the Integration of FDA Facility Evaluation and Inspection Program for Human Drugs: A concept of Operations published June 6, 2017 a for-cause facility inspection may be initiated:
In response to a new registrant or a specific event or information that brings into question the compliance and/or quality of a manufacturing practice, facility, process or drug. This type of an inspection is meant to gather additional information to determine the quality of marketed product and to determine whether enforcement actions are warranted (p. 7).
For example – report of an adverse event may trigger an FDA inspection.
Page 14 of the document provides a flow chart of the process the FDA uses to initiate, schedule, perform and follow up on the inspection. This graphic is reproduced below: