The Site Diary Entry That Started a Change Order Clock

Thursday, 16:40, level 3

Tobias has run electrical crews for nineteen years, and he writes his site diary the way he talks: short, practical, no adjectives. On a Thursday afternoon in September, standing in the corridor of a school extension on the edge of Stuttgart, he types it into Fieldwire with his thumb:

L3 corridor: ceilings still open, drywall not finished. 4 men moved to L2 again. Luminaires L3 on hold. GC site manager says new wall plan index D comes Friday.

He wrote almost the same entry on Tuesday, and a shorter one on Wednesday. Nobody in the office has read any of them. Jana, the project manager, runs four other jobs, and she reads the diaries on Friday afternoons when she can, which is not every Friday.

This is an invented firm, a 90-person electrical subcontractor with 25 live projects and six project managers. But every electrical, drywall and mechanical subcontractor in Germany will recognize the entry, because they write it every week. It is the most expensive sentence on the site, and it does not look like it.

Where the money actually goes

Jana's firm does not lose money on site. The crews are good and the estimates are sound. It loses money a year later, at a table, when the general contractor's commercial manager goes through the final account and asks one question for every claim: where is your written notice?

On a VOB/B subcontract the question has teeth. Under section 6 (1), a contractor who is hindered has to tell the client in writing and without delay. If it does not, the hindrance only counts if the client obviously knew about it and its effect. Under section 2 (6), a claim for additional work has to be announced before the work starts. The twelve extra sockets on a wall that moved, the four floor boxes the site manager asked for on a walk down the corridor, the two weeks a crew spent waiting for another trade: each is a sound claim on Tuesday and a weak one at the final account, if the paper is missing.

Jana knows all of this. What she does not have is the hour a day it would take to read 25 site diaries, a few hundred project emails and every new drawing index for the one sentence that starts a clock. So she calls me, and her first line says it all: "We don't lose money on site. We lose it on paper."

The three things I ask for first

I do not ask which AI model they want. I ask for three things, and the answers decide the whole build.

1. One closed project where a claim died for want of a notice. With its diaries, its email and the final account. This becomes the test the system has to pass before anyone relies on it.
2. Where the diaries really live. Fieldwire on the big jobs, it turns out, and a paper Bautagebuch on the small ones, which the foremen photograph. Drawings come through the general contractor's Procore project on some jobs, by email on others.
3. The contracts, including the ugly parts. VOB/B is the base, but every general contractor adds its own conditions and a negotiation protocol that overrides half of them. One of Jana's contractors wants hindrance notices addressed to a named project manager by letter. Another accepts email to a contract address.

That third answer is why the first thing I build is not the part that reads. It is a clock.

A clock before a model

For every contract, the system extracts the notice clauses with a citation to the page they came from, and Jana confirms each one. That confirmed notice profile says, for this project: hindrances go in writing, without delay, to this person, in this form. Claims for extra work are due before the crew starts. Concerns about another trade's work, section 4 (3), follow the same urgency.

From then on, deadlines are arithmetic, and arithmetic is done by ordinary code, never by the model. A "without delay" rule means the notice is due now. Day counts use working days and the public holidays of Baden-Württemberg. And the clock starts at the earliest evidence, not when someone notices it. That one rule would have saved Jana's claim on its own, because on Thursday the clock had already been running since Tuesday.

Reading 25 site diaries every day

Then comes the reading, which is the part a model is genuinely good at. Every new diary entry, project email, set of minutes and RFI answer is filed to its project and read the day it arrives. The model sorts it: possible extra or changed work, a hindrance, a concern about someone else's work, an instruction given on site, or ordinary coordination. It returns the sentence it relied on and the date the event happened. New drawing indexes are compared sheet by sheet with the previous one, so a wall that moved without a revision cloud still shows up.

Here is what happens to Tobias's Thursday entry:

The whole design is in the full blueprint for a change order and notice guard, including the VOB/B notices it watches for and how drawing comparison works.

The first version was too loud

Before it goes live, the system runs over Jana's closed project as if it were happening again, diary by diary, in date order. It catches the corridor ceilings on the day of the first entry. It also catches the extra sockets the moment index D lands.

And it raises about forty flags that were nothing: a crew moved because the lift was booked, a question about a delivery, a site manager asking where someone was. That is the real failure mode of these systems. Not missing things, but raising so many flags that the project manager stops reading them by the second week.

So the reading stays sensitive, and rules carry the precision. Only a hindrance, a concern or unstarted extra work, with enough confidence, interrupts anyone. Everything else goes on a short list Jana reads on Friday instead of the diaries themselves. Every flag she dismisses is stored with her reason, and the next version of the classifier is tested against all of them before it ships.

What stays with Jana

Nothing leaves the firm without her. She confirms every contract's notice profile, and when a supplement or a new negotiation protocol arrives, the system extracts it again and applies the stricter rule until she confirms the change. She decides whether a flag is really a hindrance. She signs and sends every notice in the form the contract demands, and the register records the sent-item ID or the registered-letter number, because a notice nobody can prove is almost as weak as none.

The system never writes to the general contractor, the architect or another trade. A notice is a legal step inside a working relationship, and Jana is the one who knows when a phone call has to come first. Diaries name workers, so the data stays in the firm's Microsoft 365 tenant, reports cover projects rather than people, and the works council hears about it before the pilot, since section 87 of the Works Constitution Act gives it a say over systems that could monitor staff.

Six weeks in, another Thursday

The ceiling contractor is late again, this time on a different job. The foreman writes the same kind of entry he always writes. At 16:52 Jana has a draft. By half past five the notice is out, with photos attached and the clock recorded. The Friday afternoon of diary reading has become a short list. And at the next final account, the question "where is your written notice?" has an answer for every claim: the register, with proof.

None of it required anyone on site to change how they work. Tobias still writes his diary with his thumb, in three lines, with no adjectives. That was the point.

If your last final account went like hers

If your projects all run in the general contractor's Procore and you are the general contractor, try Procore's own agents first. A build makes sense for subcontractors working across several general contractors' platforms, with their own diaries and German notice rules on top. It is a contained AI agent build, and the price depends mostly on how many sources each project has and how many contract variants need a profile. The full blueprint covers the rest, and the principle behind who decides what is in human-in-the-loop design.

Frequently asked questions