Punch list categories classify outstanding defects and incomplete work by how much they matter to the next stage of the project. On most industrial projects, a Category A punch item must be cleared before the next certificate (usually mechanical completion or ready for commissioning) can be signed; a Category B item can be carried past that certificate but must be cleared before a later milestone such as start-up or handover; and a Category C item is minor or cosmetic and can often be closed later, sometimes after handover. Some projects add a Category D for owner or operations requests.
Those are the common conventions, not a universal standard. The contract or the client's completions procedure defines the categories on your project, and the definitions do vary. What follows is how they are typically applied, with the questions you should ask to make them work.
What is a punch list in commissioning?
A punch list is the register of items that are defective, incomplete or not built to the approved design, found during inspection, testing or walkdowns. In completions and commissioning each punch item is raised against a specific tag and subsystem, so it can be linked to the certificate it affects.
That link is the difference between a commissioning punch list and a general snag list. A snag in a finished office fit-out affects the client's acceptance of a room. A punch item on a process plant can affect whether a system can safely be pressurised, energised or started. The category is how the project expresses that difference.
Punch list A, B, C: definitions and examples
| Category | Typical definition | Typical examples | Usually blocks |
|---|---|---|---|
| A | Affects safety, integrity, function or the ability to carry out the next stage of work | Missing or incorrect pipe support; unterminated or damaged cable; failed pressure or IR test; instrument installed in wrong orientation; missing relief valve; incorrect gasket or bolting | Mechanical completion (MCC) or ready for commissioning, depending on when raised |
| B | Does not prevent the next stage but must be cleared before a later milestone | Missing labels or tag plates; minor insulation incomplete where not needed for the test; paint touch-up; missing cable ties; small documentation corrections | Start-up (RFSU), handover (TOC) or acceptance, per contract |
| C | Minor or cosmetic; no effect on safety, operation or maintenance | Cosmetic damage to cladding; housekeeping; minor finishing items | Often nothing before handover; cleared in defects period or by agreement |
| D (where used) | Owner or operations preference, improvement or change request, often outside contract scope | Additional handrail requested by operations; relocated gauge for easier reading | Nothing, until agreed as a change |
Two variations are common enough to mention. Some clients define Category A strictly by energisation: anything that must be fixed before the system is energised or has process fluid introduced. Others define it relative to "the next certificate", so an item raised after MC might be A for ready for start-up rather than A for MC. Both are valid; the important thing is that everyone on the project uses the same one.
What makes something a Category A punch item?
A Category A item is one that would make the next stage unsafe, invalid or impossible. A useful set of test questions:
- Could this cause harm to people, the environment or equipment when the system is energised, pressurised or run?
- Would it invalidate a test that is about to be performed?
- Does it prevent a pre-commissioning or commissioning activity from being carried out at all?
- Does it breach a code or statutory requirement?
A "yes" to any of these points strongly towards Category A. A missing earth bond on a motor is A. A missing tag plate on that same motor is usually B, unless operations cannot safely identify the equipment without it, in which case some projects treat it as A for start-up.
Which certificates each category blocks
The certificate chain differs between clients, but the pattern is consistent: each certificate can only be issued when the punch items that block it are closed.
- Mechanical completion certificate (MCC): all Category A punch raised during construction and the MC walkdown closed. For more on the criteria, see mechanical completion explained.
- Ready for commissioning (RFC): all Category A items raised during pre-commissioning closed. B items from MC are tracked but may still be open. Our comparison of pre-commissioning and commissioning covers what happens between these two points.
- Ready for start-up (RFSU): usually all A items and any B items designated as start-up critical closed.
- Handover or turnover (TOC): all A and B items closed, or B items formally transferred with an agreed plan. Category C items may be listed on the certificate as exceptions.
Where this goes wrong is when the categories exist on paper but nothing actually stops a certificate being signed with open A items. That is a process control problem as much as a software one.
Who raises, categorises and clears punch items?
Roles vary, but a workable split is:
- Raised by: anyone on a walkdown or inspection: QC inspectors, completions engineers, commissioning engineers, client representatives and operations.
- Categorised by: an agreed authority, normally the client's completions or commissioning lead, or jointly on a walkdown. Categorisation by the person raising the item alone tends to inflate A items; categorisation by the contractor alone tends to deflate them.
- Action party: the contractor or discipline responsible for the fix, assigned explicitly by name or company, never "construction".
- Cleared by: the action party, who records what was done.
- Verified and closed by: the originator or an independent verifier, who confirms the fix on site. An item marked "done" by the action party is not closed until it has been verified.
That last step matters. A punch list where the action party can close its own items is a punch list where items reopen at the next walkdown.
Punch list management: good hygiene
A punch list is only useful if people trust it. These habits keep it trustworthy.
Write items so a stranger can find and fix them
Each item needs the tag number, a precise location, what is wrong and what "fixed" looks like. "Support missing" is not enough; "Line 2"-IA-1043: pipe support PS-118 missing at elevation +7.5 m, north side of rack, per isometric sheet 3" is. Attach a photo showing the tag or a recognisable reference in frame.
One defect, one item
Bundling five defects into one item means it can never be closed until all five are fixed, and you lose visibility of what is left. Split them.
Review categories on a schedule
Hold a regular punch review, weekly or more often as a certificate approaches, where the categorising authority checks new items and challenges downgrades. Reclassifying an A to a B to meet a date is one of the most common ways defects end up in commissioning.
Track ageing, not just counts
A falling number of open items can hide a small number of old, difficult A items that nobody owns. Report open items by category, by action party and by age, and escalate anything that has sat unassigned.
Avoid duplicates
On a joint walkdown, three people will spot the same missing cable gland. Check existing items for the tag before raising a new one, and merge duplicates promptly.
Close out with evidence
A closure photo taken from the same position as the original, plus the verifier's name and date, makes the record defensible when the owner audits the handover dossier.
A simple punch item lifecycle
- Raised against tag and subsystem, with description and photo.
- Categorised A, B, C (or D) by the agreed authority.
- Assigned to an action party with a target date aligned to the certificate it blocks.
- Worked and marked ready for verification by the action party.
- Verified on site by the originator or verifier; rejected back to step 4 if not acceptable.
- Closed, with evidence retained against the tag for the dossier.
Managing punch items in Accord and SnaggingTrack
In Accord, punch is managed alongside NCRs, safety items and site or technical queries, with Category A/B/C criticality and stage-gate blocking, so an open item stops the certificates it affects under the enforced certificate dependency chain. Items sit against the system and tag hierarchy, and dashboards report completion and readiness in real time.
For snagging-led projects, SnaggingTrack lets you define your own statuses and workflow, including a verify-before-close step, attach photo, video and document evidence to each item, assign due dates with overdue detection, and work fully offline on site.
Frequently asked questions
What is the difference between punch list categories and priorities?
Category describes which milestone an item blocks; priority describes how urgently it should be worked. A Category B item can be high priority if it is holding up a subcontractor's demobilisation, and a Category A item on a system not due for months may be lower priority this week. Many teams track both.
Is there a standard definition of Category A punch items?
No single standard applies across the industry. Most owners and EPC contractors define categories in their completions procedure, and the definitions are broadly similar but differ in detail, particularly in whether Category A is tied to energisation or to the next certificate. Always use the definitions in your contract or procedure.
Can a Category B item be upgraded to Category A?
Yes, and it should be when circumstances change, for example if a B item turns out to affect a test or start-up. Recategorisation should be done by the same authority that sets categories, and the change should be recorded with a reason so the history is clear.
What is a Category D punch item?
Where it is used, Category D usually covers owner or operations requests and improvements that are outside the contracted scope or not required for handover. Some projects route these into a change process instead. Not every project uses Category D.
Should NCRs be raised as punch items?
Usually not. A non-conformance report is for work or materials that do not meet specification and need a formal disposition such as repair, rework or accept as is. A punch item is for incomplete or defective work with a straightforward fix. Some projects link an NCR to a punch item so the certificate stays blocked until the NCR is closed.