2.3 IWI-S vs Basic and Comprehensive

2.3 IWI-S vs Basic and Comprehensive

Quick Answer: IAB-041 §4 defines three cumulative levels. IWI-B performs unaided VT, verifies conventional fabrication controls, and reports to a supervisor. IWI-S adds supervision of IWI-B, QC/ITP development and review, procedure-qualification witnessing, WPQR/WPS/welder-qual verification for conventional applications (arc processes, steels, aluminium), quality-document decisions, RT film quality checks (no interpretation), and NDT technique identification. IWI-C manages the whole inspection function, covers non-conventional applications, advanced DT/NDT, and acts as technical expert.

Knowing which level does what is not just career guidance — it is examinable content. Oral and written questions often present a task and ask whether it sits at Basic, Standard, or Comprehensive competence. IWI-S is additive: everything IWI-B can do remains in scope; Standard adds depth and autonomy; Comprehensive adds management and non-conventional / advanced work.

How to Read the Competence Matrix

“Conventional applications” in the Standard scope are illustrated in IAB-041 as arc welding processes, steels, and (for IWI-S document verification) aluminium alloys, with detail cross-referenced to Section 1 of the guideline. Non-conventional materials, processes, and advanced testing push toward IWI-C.

IWI-B — Basic Competence

A candidate completing Basic training shall be able to effectively perform tasks including:

Direct visual inspection

• Conduct direct unaided visual inspection to identify and evaluate welding imperfections according to acceptance criteria.

Verify, witness, and understand welding-related fabrication activities

Including (but not limited to):

• Verify the adequacy of information on NDT reports (VT, PT, MT, RT, UT) for conventional techniques — you check that the report contains the required data and is complete enough to use; you are not necessarily the NDT Level 3 writing the procedure.
• Verify data and adequacy of material certificates (base and filler materials).
• Verify identification and traceability of materials during the fabrication process.
• Verify compliance of raw materials and consumables against applicable standards, codes, and specifications.
• Verify implementation of the WPS in production for conventional applications (e.g. arc welding processes, steels).
• Verify implementation of PWHT specifications in production.
• Witness welder approval tests, including testing of specimens or test coupons.
• Witness production test coupons.
• Read and understand an Inspection Testing Plan (ITP).
• Read and understand construction drawings in relation to inspection activities.
• Report any of the above actions to a qualified supervisor.

The last bullet is the autonomy marker: IWI-B is expected to escalate through supervision rather than independently decide the full suite of quality-document acceptances that Standard and Comprehensive cover.

IWI-S — Standard Competence (Additional to IWI-B)

A candidate completing Standard training shall possess advanced knowledge enabling the following additional tasks:

People and instructions

• Supervise the activities of the IWI-B.
• Develop and provide instructions to IWI-B.

Plans and systems

• Develop, comment and review Quality Control Plans and Inspection Testing Plans based on product standards, codes, specifications, drawings, and regulatory requirements.

This is a major step up from “read and understand an ITP.” At Standard level you can build and critique the inspection plan against the governing documents — a core IWI-S differentiator on real projects and on exams.

Procedure and personnel qualification

• Witness procedure qualification tests, including testing of the specimens.
• Verify compliance of WPQRs and WPSs and welder qualifications and approvals against applicable standards, codes, and specifications for conventional applications (e.g. arc welding processes, steels, aluminium alloys).
• Verify compliance of PWHT specifications against applicable standards, codes, and specifications.
• Verify compliance of raw materials and consumables certificates against applicable standards, codes, and specifications.

Note the wording shift: Basic implements / verifies implementation of WPS and certificates in production; Standard also verifies compliance of the qualification documents themselves (WPQR/WPS/welder approvals) against the standards — and witnesses procedure qualification, not only welder approval.

Decisions on quality documents

• Take decisions on acceptance of quality documents related to welding fabrication (e.g. NDT, material testing, production testing, etc.).
• Take decisions based on quality documents (e.g. NDT, material testing, production testing, etc.) according to the requirements defined for the construction.

This is the Standard-level autonomy that Basic explicitly routes to a supervisor. You still decide against defined construction requirements — not invent new acceptance criteria.

Radiography and NDT technique selection

• Verify radiographic film quality adequacy (no interpretation).
• Identify and verify the relevant NDT techniques for a welded construction.
• Report on all the above actions.

The RT bullet is a classic exam trap. IWI-S checks whether the film/image quality is adequate (density, sensitivity/IQI, identification, technique indicators as required by procedure). IWI-S does not, under this guideline task list, perform interpretation of indications for accept/reject as the radiographer/NDT interpreter role. Keep those boundaries sharp in oral answers.

IWI-C — Comprehensive Competence (Additional to IWI-S and IWI-B)

A candidate completing Comprehensive training shall possess intimate knowledge enabling additional tasks:

• Manage the whole of the Welding Inspection activities.
• Supervise the activities of the IWI-S and IWI-B.
• Develop and provide instructions to IWI-S and IWI-B.
• Act as a technical expert for the Inspection function.
• Develop, comment and review QC Plans and ITPs for applications not covered by product standards, codes, specifications, drawings, and regulatory requirements.
• Manage inspection activities for non-conventional applications with reference to materials, processes, and advanced destructive testing and NDT techniques.

IWI-C is therefore where inspection management, novel or non-standard applications, and advanced testing live. If a scenario involves exotic processes, unusual materials outside the conventional arc/steel/aluminium envelope, advanced DT/NDT coordination at expert level, or ownership of the entire inspection organisation, the guideline points to Comprehensive — not Standard.

Side-by-Side Task Map (Exam Memory Aid)

Exam Traps and Oral Phrasing

Trap 1 — RT interpretation. “IWI-S interprets radiographs for crack acceptance” is false under the IAB-041 task wording. Correct: IWI-S verifies film quality adequacy; interpretation is outside that listed Standard task.

Trap 2 — Writing the ITP. Basic reads and understands the ITP. Standard develops, comments, and reviews QC plans and ITPs based on product standards and codes. Comprehensive does the same for applications not covered by those documents.

Trap 3 — Procedure vs welder qualification. Basic witnesses welder approval tests. Standard adds witnessing procedure qualification and verifying WPQR/WPS compliance against standards.

Trap 4 — Conventional vs non-conventional. Standard verification scope for WPQR/WPS/welder quals is framed around conventional applications (arc processes, steels, aluminium alloys). Non-conventional materials/processes and advanced DT/NDT management are Comprehensive.

Trap 5 — Autonomy. If the task ends with “report to a qualified supervisor,” think Basic. If it includes “take decisions on acceptance of quality documents,” think Standard. If it includes “manage the whole inspection function” or “act as technical expert,” think Comprehensive.

Why This Matters on Real Jobs

On a conventional steel fabrication under ISO 3834 with arc processes, an IWI-S can own day-to-day supervision of Basic inspectors, maintain ITPs, witness qualifications, and release quality documents against the construction requirements. When the project introduces non-standard materials, novel processes, or needs a single technical authority for the entire inspection organisation, the competence model expects IWI-C depth. Matching person level to task risk is itself a quality decision — and it starts with knowing the matrix in IAB-041 §4.

Connecting Back to Lifecycle Duties

Sections 2.1 and 2.2 described what inspectors do across the weld lifecycle and how they report. Section 2.3 answers who is competent to do which part of that work. For your IWI-S exam preparation, assume Standard-level ownership of conventional arc welding on steels and aluminium: you supervise Basic staff, own ITP/QC plan quality, verify procedure and personnel documents, decide on quality records, check RT film quality without interpreting indications, and select appropriate NDT techniques — then report those actions with the same quantified, traceable discipline required of every level.