What is a DLP defect register?
DLP stands for defects liability period: the period set by a construction contract, after the works are completed, during which the contractor remains responsible for putting right defects in its work. A DLP defect register is the list of those defects and the record of their rectification. In a tunnel it is usually issued by the engineers as a master defect list, often a spreadsheet with an item reference, the tunnel drive, the ring number, the clock position, the defect type and a comment or instruction for each row. Running the register means turning that list into work for the crews, recording what was done to each defect, getting each repair accepted, and being able to show at any point how much of the list is closed. On Sydney Metro West Portion 1, the issued DLP master defect list brought 3,158 defects into DEFECTED.
How do you get the issued list into the register without retyping it?
Import it, and keep its references. In DEFECTED a project engineer or admin uploads the issued Excel file, and the importer reads it in steps: upload, validate, preview, commit. Validation checks every row and puts problem rows into review with a reason, such as a blank or duplicate item reference, a blank defect type, a ring number it cannot read or a defect type it does not recognise. Defect types from the file are matched to the app's taxonomy, tolerant of case, spacing and known alternative names. The preview shows exactly what will be added and changed before anything is written. Every imported defect keeps its item reference from the issued list, so the register can always be read back against the engineer's own document, and a later issue of the list updates the same defects rather than creating duplicates.
How should DLP defects be split and assigned?
By the kind of work, then by who is doing it. Each defect type in DEFECTED belongs to a work stream: injection for leaks, wet cracks and gaps; labour for items such as spalls, dry cracks, drill holes and cleaning; investigation for damaged ferrules. A defect can also be marked no action, or left pending assignment when its stream is not yet known. Crews see only their own work stream, filtered to the tunnel they are in, so an injection crew is not scrolling past labour items and the other way round. Within a stream, a defect is assigned to a company and an operator, which lets several subcontractors work the same register with the work attributed to each. A printable work list gives a crew its share of the list on paper as well, for a heading where that helps.
What evidence should each closed DLP defect carry?
Enough that someone who was not there can accept the repair. For every defect DEFECTED keeps a before and an after photo taken from inside the defect, with the capture time burned into the image; the work sessions, each with the person, company and the day the work happened; and, for injection, the packers installed, injected and patched and the product drawn from a kit, with its batch and the litres. The engineer's instruction from the issued list stays on the defect. Every status change, from logged to done to validated, is written to the defect's history by the database with who made it and when, and the comments that came with a send-back or a reopen are kept word for word. Because the crew records this at the defect, nothing has to be pieced together from phones and spreadsheets at the end of the period.
The injection records guide goes field by field through what an injection repair should carry.
How does a defect move from done to closed?
Through an engineer. When a crew finishes a defect it is marked Done, which in DEFECTED means awaiting validation, and it cannot be marked done until the after photo is attached. The defect then joins the engineer's queue, oldest first, filterable by tunnel, cross passage, company, work stream or defect type. The engineer checks the photos, the packers, the product, the work sessions and the history on one screen and either validates the defect, which closes it, or sends it back with a required comment. Validation can be done one defect at a time or for a selected batch. The database accepts a validation only from an engineer or admin of that project, through its own function, and only for defects that are actually awaiting validation. Validated is the only status that means closed.
What happens when the defect list is reissued?
The new issue is imported over the old one, matched on item reference. The preview lists the classification changes the new file would make, row by row, and new rows are added. In full master mode, rows missing from the new issue can be retired from the register, but only after an explicit confirmation, and retiring is a flag on the defect, not a deletion. Status columns in the file are handled conservatively. A row the file marks done can close a defect that has no field work on it. A defect where work is already recorded is flagged as a conflict for a person to decide, existing injection defects are never closed by a file, and a defect completed in the app but still open in the file is shown as the app being ahead. The review lists can be downloaded as CSV for the engineer issuing the list.
How do you report close-out to the client?
From the register itself, so the figures cannot drift from the work. Each shift produces a daily work record: rings, clock positions, packers, product, photo pairs and status. The principal contractor gets a weekly report across companies, including first-time validation and rework rates by company and by crew. The register exports as CSV, and as PDF or Excel by day, week, month or ring range; closeout photos export as a ZIP of the original after photos with a manifest; and an audit pack bundles a period's exports into one ZIP with an index. Projects that use Autodesk Construction Cloud can export validated defects as ACC upload files, with DEFECTED tracking which have already been sent and which were validated again after a reopen.
A DLP close-out checklist
- Import the issued list with its item references; clear every row in review
- Check each defect type maps to a work stream; resolve anything pending
- Assign companies and operators; give each crew its stream and tunnel
- Capture before and after photos, packers, product and sessions at the defect
- Validate or send back every Done defect; nothing is closed without it
- Re-import each reissue against the same references and settle the conflicts
- Report from the register: daily records, weekly report, exports and photo packs
The register itself is described on the tunnel defect register page, and the Sydney Metro West Portion 1 case study shows a DLP list worked this way. To run your own list through it, start a 14-day pilot.