What Is Vendor Inspection? Roles & Responsibilities

Vendor inspection is the buyer’s QA/QC at the supplier’s works to verify materials and equipment against the PO, drawings, and referenced standards. It covers ITP/QCP review, staged in-process checks, witness/hold points, FAT, and documentation. Inspectors collect objective evidence and accept/reject strictly per API/ASME/ISO/EN referenced by the project spec.

 

 

Vendor Inspection — Plain Definition (clear & practical)

Vendor inspection (a.k.a. supplier or source inspection) is product/job-focused QA/QC performed at the manufacturer or sub-vendor to confirm conformity before shipment. It aligns the ITP (Inspection & Test Plan), witness/hold points, and acceptance “as per API/ASME/ISO/EN referenced by the project spec.”

Where it happens

• Supplier’s fabrication/assembly line
• Sub-vendor special processes (e.g., heat treatment, coatings, NDE)
• Factory Acceptance Testing (FAT) bays and certified test labs

Scope vs. vendor audit

• Inspection = does this item/job meet PO/drawings/ITP and the referenced standard?
• Audit = does the quality management system meet ISO 9001 or buyer requirements?

 

Why Vendor Inspection Matters (outcomes, not fluff)

• Prevents cost & delay: catches nonconformities before shipment/site works.
• Compliance by design: acceptance is applied per the cited clauses (no ad-hoc limits).
• Traceability you can trust: MTCs, calibrated instruments, tagged photos, IRs/NCRs tied to serials.
• Risk-based visibility: right witness vs hold points at the right stages.
• Smoother FAT & release: clean dossiers, reduce punch lists and disputes.

 

TPI vs. In-House Inspector (quick rule-of-thumb)

• Third-Party Inspection (TPI): independent assurance for high-risk/critical equipment, remote vendors, or when buyer bandwidth is limited.
• In-house/buyer’s inspector: when deep product knowledge or close coordination with engineering is key.
  Either way, acceptance remains per the project-referenced API/ASME/ISO/EN.

 

Roles & Responsibilities in Vendor Inspection (RACI)

Goal: remove ambiguity. Every task has one Accountable, clear Responsible parties, and informed C/I stakeholders. Acceptance is always per API/ASME/ISO/EN referenced by the project spec.

RACI Matrix (example — adapt to your PO)

Task / Deliverable	Buyer/Owner QA	EPC / SQE	Manufacturer QA/QC	TPI	End User/Ops
Prepare QCP/ITP	C	C	R	C	I
Approve ITP & W/H points	A	C	C	C	I
Notify visits (1–2 wks)	C	R	R	R	I
Document screen (PO, dwgs, MTCs, cal certs)	A	R	R	C	I
In-process surveillance	A	C	R	R	I
Special processes (weld/HT/coat/NDE)	A	C	R	R	I
FAT execution & records	A	C	R	R	I
Issue IR (inspection report)	A	C	R	R	I
Raise/close NCR	A	C	R	R	I
Gauge/instrument calibration control	I	C	R	C	I
Final dossier compilation	A	C	R	C	I
Release note/shipping clearance	A	C	R	C	I

Need a working ITP? Grab the vendor inspection ITP template to align tasks, witness/hold points, and records.

 

Buyer/Owner QA/QC — Accountability & Acceptance

• Owns acceptance: applies criteria as per referenced standards in the PO/ITP.
• Approves ITP/QCP; defines W/H points and evidence required.
• Reviews/approves deviations/concessions; signs release.
• Ensures traceability (tags/serials), calibration policy, and dossier completeness.

Manufacturer QA/QC — Execution & Evidence

• Prepares QCP/ITP; controls fabrication, special processes, and sub-vendors.
• Ensures calibrated instruments, qualified procedures/personnel.
• Runs FAT to approved procedures; compiles IRs, charts, MTCs, certificates, photos.
• Delivers a clean final dossier mapped to item/tag and ITP.

Third-Party Inspection (TPI) — Independent Verification

• Performs surveillance to the approved ITP; witnesses W/H points.
• Issues IRs with objective facts (readings, clause refs, instrument IDs).
• Raises NCRs when acceptance isn’t met; verifies corrections/re-tests.
• Maintains independence; reports to the buyer/owner.

EPC / Supplier Quality Engineering — Coordination

• Aligns schedule, readiness, and notifications; ensures sub-vendor coverage.
• Tracks actions from IR/NCR to closure; keeps stakeholders C/I as agreed.
• Checks that procedures cite the correct standard/edition.

End User / Operations — Service Criticality

• Provides service-critical requirements (e.g., shutdown impacts, operability checks).
• May witness FAT for function/controls; remains Informed on quality status.

 

Handover Essentials (don’t skip these)

• Before first visit: approved ITP/QCP, latest drawings/datasheets, referenced standards list, test procedures, calibration status.
• At FAT start: readiness sheet, tag/serial list, gauge IDs and valid cal certs, safety permits.
• At release: signed IRs, NCR log (closed), test charts, MTCs/CoC, NDE reports, photos, release note—all per project spec.

 

The Vendor Inspection Process (PO → Release)

Step 1 — Contract Inputs & Kick-off

• Gather baselines: PO, datasheets, drawings/BOM, manufacturing schedule, sub-vendor list.
• List referenced standards: API/ASME/ISO/EN as named in the project spec (no ad-hoc criteria).
• Draft QCP/ITP: define stages, witness (W) and hold (H) points, objective evidence required.
• Comms & notifications: who invites whom, lead-times (e.g., 7–14 days), site safety/permits.

Need a structured starter? Use the vendor inspection ITP template to align W/H points and records.

 

Step 2 — ITP/QCP Review & Approval

Align the ITP with risk, schedule, and acceptance per the standards referenced by the project spec.

ITP Review Checklist (paste into your doc)

Item	Reference	Acceptance reference	Status	Action owner
Latest drawings/datasheets listed	PO / doc register	Per order	☐
Each stage has W/H point defined	ITP §…	Per project spec	☐
Test procedures cite correct standard/edition	Procedures	Per referenced standard	☐
Records required (charts, MTCs, cal certs, photos)	ITP §…	Per project spec	☐
Sub-vendor controls included	QCP §…	Per project spec	☐

 

Step 3 — In-Process Surveillance & Special Processes

Monitor manufacturing and special processes; apply acceptance per the cited clauses (welding, heat-treat, coating, NDE).

Stage Control Plan (example)

Stage	Key checks	Acceptance reference	Records
Casting/forging receipt	ID/qty, condition, certs	Per order & referenced standard	IR, photos
Welding & WPS/PQR	Welder quals, parameters	Per ASME IX/ISO welding as referenced	Logs, WQRs
Heat treatment	Cycle, soak, charts	Per project spec/standard	HT chart, IR
Coating/lining	DFT, cure, holiday test	Per project coating spec	DFT log, photos
Dimensional checks	F2F, flanges, interfaces	Per drawings/standard	Sheet, IR

Reduce repeat NCRs with preventive controls and staging—see prevent vendor nonconformities.

 

Step 4 — FAT (Factory Acceptance Testing)

Run functional/performance tests to approved procedures; instruments must be calibrated and traceable.

FAT Readiness Checklist

Item	Status	Evidence
Approved procedures on bench	☐	Rev/date
Gauge/recorder cal certs valid	☐	Cert IDs
Tag/serial list printed	☐	List v…
Safety permits (LOTO, pressure)	☐	Permit IDs
Witness roster confirmed	☐	Emails

During FAT

• Record readings, instrument IDs, and photo IDs.
• Acceptance is per API/ASME/ISO/EN referenced by the project spec (do not invent values).
• Log deviations immediately; contain, correct, re-test.

 

Step 5 — Dossier & Release

Compile objective evidence; map every record to item/tag.

Final Dossier Index (starter)

Section	Contents	Acceptance reference	Signatures
Admin	PO, datasheet, drawings	Per order	Buyer/Vendor
ITP/QCP	Approved copies, W/H log	Per project spec	Buyer
Material	MTCs, trace map	Per referenced standard	Vendor
Process	Welding/HT/Coating records	Per referenced standard	Vendor/Inspector
Tests	FAT charts, setpoints	Per referenced standard	Inspector
NDE	Reports, maps	Per referenced standard	Level II/III
NCRs	Log, dispositions	Per procedure	Buyer
Photos	Tagged, dated	Per project spec	—
Release	IRs, release note	Per order	Buyer

 

Witness & Hold Points (How to Set Them)

Typical W/H Map (risk-based)

Stage	Risk rationale	W/H	Acceptance reference	Required records
First-article dimensional	Fit-up risk	W	Per drawings/standard	Dim sheet, IR
Weld procedure/qualification	Pressure boundary	H	Per welding standard referenced	WPS/PQR/WQR
Heat treatment cycle	Mechanical props	W	Per project spec/standard	HT chart
NDE on critical welds	Hidden defects	W	Per NDE standard referenced	NDE report/map
Performance/FAT	Function & safety	H	Per API/ASME/ISO/EN referenced	Charts, photos
Final inspection & dossier	Shipment readiness	H	Per order/spec	Signed index, release

Practical tips

• Tie W/H to highest risk and irreversible steps.
• Define prerequisites (e.g., “Do not proceed to FAT until cal certs verified”).
• Set notification windows and alternates to avoid slips.
• Use clear pass/fail language: “Acceptance as per clause X of the referenced standard.”

Vendor Inspection Standards & Acceptance (placeholders, no numbers)

Rule: do not invent values. Apply acceptance as per API/ASME/ISO/EN referenced by the project spec and the edition named in the PO/ITP.

Quick Reference Map (use only if referenced by your project)

Area	Common standard (if applicable)	How it’s used in vendor inspection
Pressure/functional tests (valves/packages)	API 598; ISO 5208; EN 12266-1/2	Tightness/shell tests at FAT per referenced clauses
Pressure equipment design/tests	ASME VIII / EN 13445 (where applicable)	Hydro/ pneumatic tests per spec; dossier evidence
Piping/fabrication	ASME B31.x / EN piping codes	Dimensional/NDE per referenced sections
Dimensions & flanges	ASME/EN B16 series (as named)	Face-to-face, bolt circles per drawings/standard
Welding & brazing	ASME IX / ISO 15614/9606	WPS/PQR/WQR per referenced welding code
NDE methods	ASME V / ISO 17635 et al.	PT/MT/UT/RT extent & acceptance per project
Materials & MTCs	EN 10204 (cert types)	Trace heats to tags/serials; certificate validity
Coating/lining	Project coating spec; ISO series (as named)	DFT/holiday/cure checks per spec
Calibration & labs	Project calibration procedure; ISO/IEC 17025 (labs)	Valid cal certs matched to instrument IDs

Always cite: “Acceptance per <standard/edition> referenced by the project spec.” Do not restate numeric limits.

 

Examples & Templates (copy/paste into your program)

Vendor Inspection IR (Inspection Report) — Field Set

Field	What to record
Supplier / Location	Works, bay, sub-vendor if any
PO / Item / Tag-Serial	Exact identifiers (match to dossier)
Stage / W/H point	From approved ITP
Procedure & Standard reference	Doc IDs + clause/edition as referenced
Instruments	IDs + valid calibration
Observations	Measured values, photos (IDs), defects
Result	Conform / NCR raised
Attachments	Charts, MTCs, NDE, photos
Inspector & Buyer	Names, signatures/date

NCR Workflow (practical, fast)

1. Contain: stop use/ship; mark item/tag.
2. Correct: repair/rework per approved procedure & standard reference.
3. Verify: re-inspect/re-test; record clause and readings.
4. Concession (if needed): buyer QA approves or rejects.
5. Close: update dossier; prevent recurrence (link to CAPA).

Release Readiness Checklist

• Approved ITP/QCP; all W/H signed.
• IRs, charts, NDE, MTCs/CoC mapped to tags/serials.
• Calibration certificates current and referenced in reports.
• Deviations/NCRs closed or concession approved by buyer.
• Final dossier index signed; release note issued.

 

When the Item Is a Valve

Inspecting valves? Use our dedicated, step-by-step guide: Valve Inspection Checklist — visual/markings, dimensional, materials/traceability, and pressure/functional tests with placeholders as per API 598 / ISO 5208 / EN 12266 referenced by your project.

 

FAQs — Vendor Inspection

What is vendor inspection?
Buyer’s QA/QC at the supplier to verify conformity to the PO/drawings and referenced standards via ITP-driven checks, W/H points, FAT, and documentation.

Who prepares and who approves the ITP?
The manufacturer prepares; buyer/owner QA approves. TPI may review. Acceptance follows the standard/edition referenced by the project.

What’s the difference between expediting and inspection?
Expediting drives schedule/readiness; inspection verifies quality and acceptance per standards.

Are witness and hold points mandatory?
Where the ITP defines them and the buyer requires them. Use W for visibility, H where irreversible risk exists.

Which standards apply to vendor inspection?
Only those named in the project spec/PO (e.g., API/ASME/ISO/EN). Apply acceptance per the cited clauses—don’t invent limits.

What must be in a final supplier dossier?
Approved drawings/ITP, IRs, test charts, MTCs/CoC, NDE, certificates, photos, deviations/waivers, and release note—as required by the order.

Who raises and who closes NCRs?
Inspector (buyer/TPI) can raise; the buyer/owner approves concession/closure after verified correction.

Can TPI replace in-house inspection?
TPI adds independence; use for high-risk items or vendor locations. Acceptance remains per project-referenced standards.

 

Download: Sample ITP & IR Forms (ZIP)

Filename: Sample_ITP_IR_Forms.zip

• Editable ITP template with W/H points and acceptance placeholders per referenced standards.
• Inspection Report (IR) form + NCR register to track findings and dispositions.
• Final dossier index to standardize evidence and speed release.

CTA: Download the Sample ITP & IR Forms (ZIP) and start your vendor inspection program today.

 

Vendor Inspection Training — Upskill Your Team

Want structured practice and real checklists? Join Vendor Inspection Training — plan ITPs, set witness/hold points, run FATs, and apply acceptance as per the standards your projects reference.

 

Vendor Inspection vs Expediting vs Audit (clear comparison)

Topic	Vendor Inspection	Expediting	Vendor Audit
Primary aim	Verify product/job quality against PO/drawings and referenced standards	Drive schedule/readiness, materials on time	Assess QMS/system capability
Evidence	Measurements, charts, IR/NCR, photos, tag/serial traceability	Milestones, dates, material arrival, manpower	Procedures, records, internal audits
Tools	ITP/QCP, witness/hold points, FAT	Look-ahead plan, risk log, recovery plan	Checklist vs ISO 9001 or buyer criteria
Acceptance	Per API/ASME/ISO/EN referenced by project spec	N/A (schedule metrics)	Conformance to system requirements
Outcome	Release note / ship-clearance (or NCR)	Schedule recovery actions	Audit report & CAPA
Who leads	Buyer QA/QC / TPI	Project controls / expeditor	Supplier quality / buyer audit team

 

Email Templates (plug-and-play)

1) Vendor Inspection Notification (W/H point)

Subject: Inspection Notification — PO [####], Item/Tag [####], [W/H] at [Vendor, City] on [Date]

Hello Team,
As per the approved ITP, we plan the [Witness/Hold] for [Stage: e.g., FAT / NDE / Dimensional] on [Date, Time, Timezone] at [Vendor, Address].

References: PO [####], Drawing/Datasheet [IDs], Procedure [ID/Rev], standard/edition as referenced by project spec.
Readiness: procedures at bench, tag/serial list, valid calibration certificates for instruments to be used.
Please confirm attendance or share alternates.

Regards,
[Name], Buyer QA/QC

2) FAT Agenda & Readiness Check

Subject: FAT Agenda — PO [####], Package/Valve [####], [Dates]

Attached: FAT steps, hold/witness points, instrument IDs & cal certs, safety permits.
Acceptance will be applied as per API/ASME/ISO/EN referenced by the project spec.
Kindly acknowledge readiness and provide any constraints 48h prior.

— [Name], Supplier Quality

 

Inspection Report (IR) — worked example (concise)

• Supplier / Location: Acme Valves, Bay 3 (Sub-vendor: Seat Overlay Ltd.)
• PO / Item / Tag-Serial: PO 450123 / Gate Valve DN150 / GV-0150-A01
• Stage / W/H: FAT — Hold (H)
• Procedure & Standard Ref: FAT-VAL-012 Rev.2; acceptance per API 598 (edition per project spec)
• Instruments: Pressure gauge G-245 (cal valid), Recorder R-009 (cal valid)
• Observations: Hydrostatic shell test run; stabilization achieved; no visible leakage; seat leak test per procedure; readings attached (Charts C-112 to C-114).
• Result: Conformant to referenced clauses; No NCR
• Attachments: Charts C-112…C-114; photos P-021…P-030; tag map; cal certs list
• Inspector / Buyer: J. Smith (TPI) / A. Novak (Buyer QA)

(Note: no numbers quoted; acceptance tied to the standard referenced by the project.)

 

One-Page Pocket Checklist (on-site use)

Before you start

• Approved ITP/QCP on the table; correct standard/edition listed.
• Latest drawings/datasheets; tag/serial list printed.
• Calibration certificates valid and mapped to instruments.

Sequence

1. Documentation screen (PO, procedures, MTCs, cal certs).
2. Visual/markings (nameplate, size/class/material, preservation).
3. Dimensional (F2F, flanges/threads, interfaces) — acceptance per drawings/standard.
4. Materials & traceability (MTCs; PMI/hardness if specified).
5. NDE (if required) — extent/acceptance per referenced clauses.
6. FAT (hydrostatic, seat leak, functional) — as per API/ASME/ISO/EN referenced by project.
7. Close-out (IR, NCR if any, charts, photos, final dossier index, release note).

Golden rules

• Record facts (values, IDs, photos), not opinions.
• Never choose ad-hoc leakage categories or hold times; use the referenced standard.
• Every record maps to one tag/serial.

 

Where to Go Next (one click each)

• Build your plan: Vendor Inspection ITP Template
• Avoid repeat findings: Prevent Vendor Nonconformities
• If your item is a valve: Valve Inspection Checklist

Training for your team?
Enroll in Vendor Inspection Training — plan ITPs, set witness/hold points, run FATs, and apply acceptance as per the standards your projects reference.