Same number, different value
Project margin calculated after delivery and project margin calculated during it are the same arithmetic and completely different things.
Afterwards it is history. It explains what happened, everyone agrees it was unfortunate, and it changes nothing about the project it describes. During, it is a choice: talk to the client, change the approach, move somebody, or decide knowingly to absorb it.
Why it arrives late
Because the three numbers live apart. What was sold is in the proposal or the CRM. What it is costing is in timesheets, if they are current. What has been billed is in accounting.
Assembling them takes a person a day, so it happens quarterly. And it happens quarterly for a completely rational reason: nobody can justify a day of finance time per project per week. The frequency is set by the cost of assembly, not by when the number would be useful.
The overrun is never a surprise to everyone
This is the part that stings. On almost every project that loses money, somebody knew in week three.
Usually the person doing the work. They could see the estimate was wrong and the client was slower than assumed. They mentioned it, or half-mentioned it, and it did not reach anyone who could act because there was no number attached and no place to put it.
So the information existed and the mechanism did not. That is not a people problem, and treating it as one — asking teams to escalate earlier — reliably fails, because they did.
What live actually requires
Three things, none dramatic. Hours logged against the work rather than a project code, so cost is real without a coding step. Cost rates that mean something, including employer costs and non-productive time. And revenue read from what was actually contracted and invoiced.
Then margin is a figure you look at rather than commission, and the conversation moves to week three, where the options still exist.
One caveat. Live margin makes overruns visible, which is uncomfortable before it is useful. Teams that have never seen it are often alarmed by projects they thought were fine. They were never fine — they were unmeasured, which is a different thing that felt the same.