Would your change records survive an inspection?

Maintenance replaces a discontinued diaphragm valve on a WFI loop with the manufacturer's successor model, described in the catalogue as a direct replacement. The diaphragm material is different. No change control is raised. What is this?

• AA like-for-like replacement; the catalogue says it is a direct replacement
• BA change to a critical utility made without evaluation, which needs a change control and an equivalence or requalification assessment
• CA maintenance activity covered by the preventive maintenance procedure
• DAcceptable provided the next WFI sample passes