Inspection Planning and Preparation
Start with the contract, not the form
Before you travel to a supplier's plant, build the inspection plan from the purchase order, the referenced product specification (an API product standard, or API Q1 for the quality program), the drawings, and any buyer supplemental requirements. The supplier's inspection and test plan (ITP) is the working map: it lists operations, characteristics, acceptance criteria, and inspection points. Learn the three surveillance designations and never blur them - a hold point stops work until the inspector and buyer are satisfied, a witness point requires notification and gives the buyer the option to attend, and a monitor or review point is a records check that can be completed later.
Traps: a generic ITP copied from another job that omits a PO requirement; missing revision control; inspection lines listed without acceptance criteria; and assuming an ISO 9001 certificate substitutes for product-specific requirements. Check that gauges and test equipment are calibrated, that NDE, welding, and heat-treat procedures are approved and available at the point of use, and that sub-tier suppliers are identified. A hold point cannot be created or waived after the fact; if the supplier proceeds past one without notification, that is a nonconformance, not a scheduling inconvenience.
Worked example: the PO requires customer witness of the hydrostatic test, but the ITP shows 'M'. Raise it at the pre-inspection meeting, obtain a buyer-approved ITP revision, and only then agree the test date. Rule of thumb: no approved ITP line, no test - document the gap before work moves.