ON A REAL WEEK
What it looks like.
The version that goes out the door is the one nobody had time to check.
The number was finished at four. The document got built at five, by whoever was still there, from the last thing they were sent — which is not always the last thing that changed. It goes out because the clock says it has to. The check that would have caught it is the step there was no room for. When the proposal comes off the estimate itself, the last number that changed is the one that goes out, and there is no second document to check against the first.
Precon and estimating are not looking at the same list.
Precon is tracking what the company intends to chase. Estimating is working whatever landed in the inbox this week. The two lists overlap and nobody can say by how much. Somebody finds out at the wrong moment that a job everyone assumed was covered has no owner on it. One list of what you are chasing, with what you know about each job attached, is the first thing Bid gives you.
The won job hands the floor a total, not a BOM.
You priced every piece of it to win. What crosses to the shop is a contract value and a set of drawings. The quantities that produced the number are sitting in a file somebody would have to go and find, so the floor takes the job off again from scratch. You pay for that count twice: once in the estimate and again on the floor. Bid hands the floor the BOM the estimate was built from, so the count gets done once.