The most important number on a job is not what you have spent. It is what the job will cost when it is done: the estimate at completion (EAC). EAC is cost to date plus estimated cost to complete (CTC).
The weak way to get CTC is "revised budget minus cost to date". That quietly assumes every remaining dollar will land exactly on budget, even on codes that are already overrunning. A better CTC is built from what is left: remaining quantities times realistic rates, plus open commitments, plus known exposure such as unpriced changes.
A quick cross-check is the percent-complete method: if a scope is physically 58% complete and has cost $2.61M, a straight-line projection says about $4.5M at completion. When the bottom-up CTC and the projection disagree, that gap is where the conversation should start.
CTC should be reviewed by the person who knows the work, every month, code by code. The output is the projected over or under budget on each code, and the projected gross profit on the job. That forecast feeds everything downstream: WIP, revenue recognition, cash planning and what you tell your surety.