Source Inspection Fundamentals, Roles, and Quality Surveillance Planning
Purpose and roles
Source inspection is the purchaser's verification, performed at the vendor's works, that equipment is built to the purchase order, the technical specification, and the governing code. The inspector does not replace the vendor's quality organization and never accepts work on the vendor's behalf. Keep four roles distinct: the purchaser or owner (defines requirements), the vendor's QC function (performs inspection and carries the code-stamp responsibility), the source inspector (witnesses, verifies, documents), and any jurisdictional or code authorized inspector, whose statutory sign-off cannot be delegated to the source inspector. A frequent exam trap is treating the source inspector as the authorized inspector or as someone who can grant a code deviation. The inspector can only record and report a deviation; accepting a nonconformance needs the purchaser's written approval and, where the code is affected, the authorized inspector's approval as well.
The surveillance plan
The inspection and test plan (ITP) is the core planning document. It lists each activity, the acceptance criteria, the record produced, and the point type: hold, witness, review, or monitor. A hold point stops the work until documented acceptance is given. A witness point requires notification but does not stop the work if the inspector declines to attend. Review points are document checks after the activity; monitor points are unobtrusive surveillance. Other planning inputs are the vendor quality plan, approved procedures, drawing register, and shipping schedule.
Worked example
An ITP lists weld-root visual inspection as a witness point and the hydrostatic test as a hold point. The vendor completes the root pass at 22:00 without notifying you and calls only before the hydrotest. The root pass is a notification lapse to record, not automatically a rejectable nonconformance; the hydrotest cannot proceed without your documented hold-point release.
Rule of thumb
If the ITP says hold, the product does not move forward until you sign.