Complaint
The ISO 13485 definition is wide on purpose: a remark during a service visit or a phone call counts, and so does a problem with a service that affects how the device performs. The complaint process decides whether each one is also a reportable event, which is why the definition and the vigilance rules are read together.
written, electronic or oral communication that alleges deficiencies related to the identity, quality, durability, reliability, usability, safety or performance of a medical device that has been released from the organization’s control or related to a service that affects the performance of such medical devices Note 1 to entry: This definition of “complaint” differs from the definition given in ISO 9000:2015.
ISO 13485:2016, clause 3.4