Collapsed as-built (but-for)

Where a time impact analysis adds a delay to see the push, a collapsed as-built works the other way: it starts from what actually happened and removes one party's delays to show when the job would have finished but for those delays. It's the natural choice when the work is finished or well along and you're arguing "we'd have been done weeks earlier if not for them."

Note: A few terms, in plain language. As-built is the schedule of what actually happened. But-for is the finish date "if that delay hadn't occurred." Collapsing means taking the delays out and letting the schedule recalculate to that earlier date.

Step 1: Set up the as-built

In the chat panel, click + (New thread), type collapsed in the search box, and pick Collapsed as-built under Delay analysis specialist. In a thread that's already with that agent, use the Flows button under the message box. See Analyze a delay for both routes.

Step 1 of 3 of the Collapsed as-built flow, with the as-built schedule, whose delays to remove, and the concurrency theory to choose.1231As-built schedule: the current schedule, or upload one.2Whose delays should be removed? Owner or contractor.3Concurrency theory: how to treat two delays at once.
  • As-built schedule: your Current schedule, or Upload as-built (P6 XER/XML, MPP or Excel). The collapse needs a logic-driven as-built: actual dates plus the relationships between activities.
  • Whose delays should be removed? Owner delays (the contractor's "we'd have finished early but for the owner" case) or Contractor delays (the owner's case).
  • Concurrency theory: how to treat two delays happening at once. Functional counts delays on the same controlling path in the same analysis period as concurrent, even if not on the same days; Literal counts only delays on the very same days. This matters because a delay that runs alongside the other side's delay usually can't be claimed by either party alone.

Step 2: Describe the delays to remove

Describe the events attributable to that party, what they were and roughly when, and attach your evidence (a delay log, change orders, RFIs). If you attach a delay log and leave the description short, the agent takes every event in it attributed to the party you picked. Check your answers on the last step and press Start.

Step 3: Review the extraction set

The agent proposes the extraction set: for each delay, the as-built activity or duration it will remove, and why. It also lists the other party's delays that stay in, because they're the concurrency in the result, and anything it couldn't verify.

The agent's proposed extraction set, a table of two owner delay events with the activity, as-built duration, change and days removed, below an answered question card asking for the go-ahead.1231The question card: go ahead as proposed, or say what to change.2The extraction set: each delay, the activity it maps to, and how many days come out.3The delays that stay in, and why they matter for concurrency.

Check it before it runs. If a delay is mapped to the wrong activity or you disagree with a duration, answer the card with the change. Nothing is removed until you approve.

Step 4: Read the result

Once you approve, the agent builds a scenario from the as-built, first checks that the unchanged as-built recalculates to its actual finish, then removes the agreed delays and recalculates to the but-for completion date. Your working schedule doesn't change.

The collapsed scenario open in a tab, marked draft with 2 changes, its Gantt showing the as-built activities with the shortened review highlighted; the chat beside it shows the agent's plan and the answered question card.12341The scenario is a draft copy of the as-built.2~2 changed: the two delays that were taken out.3The scenario sits under Scenarios in the project tree.4A changed activity is highlighted on the Gantt.

You get a report document under Documents (for example, Collapsed As-Built (But-For) — Owner delays) and the collapsed scenario. The result is the gap between the two dates: in this example, as-built Substantial Completion was 10 April 2026 and the but-for date is 20 March 2026, so 15 working days are on the owner. The report breaks that down by event and says which delays added nothing because float absorbed them.

Heads up: The scenario has a Merge into schedule button, as every scenario does. Don't merge an analysis scenario: it's the record of what was removed, not a plan to follow.

Ask Owl
Also remove the owner's late RFI responses in March and re-collapse.
Treat the two June delays as literally concurrent instead of functional.
I've attached the spec section and the geotech report. Check the review period and the rock finding against them.

What to do next

  • Compare methods: a time impact analysis on the same events is a good cross-check; the two should tell a consistent story.
  • Send it: export the but-for report for your claim.