Job cost reviews stall while you argue about whose number is right.

Everyone shows up to the job cost review with a number. The PM has Procore open. The controller has the ERP. Somebody has the schedule of values in a spreadsheet that has quietly become the real record for that job. The three do not agree, and the first twenty minutes go to figuring out which one is wrong instead of what to do about the job.

Then it does not get resolved. It gets deferred, because resolving it means someone tracing a commitment back through two systems, and nobody in that room has the afternoon. So the meeting proceeds on the number belonging to whoever argued hardest, and the same delta shows up next month.

"Single source of truth" has meant one thing in this industry for twenty years: consolidate onto a new platform, migrate the data, retrain the field, and discover in month eight that the spreadsheets came back. Anyone who has been through that implementation is right to be skeptical. That is not what this is.

Your systems of record stay authoritative. Procore stays the record for project management. Your ERP stays the record for cost. The single source is the place your team asks the question, not the place the data lives. Ask what committed costs are on Riverside and the answer comes back with the figure, the system it came from, and when that system was last read.

When two sources disagree, you see both. Every answer shows the underlying data it was built from, so a delta between Procore and accounting is visible in the answer itself rather than discovered later. Nothing gets averaged, and nothing quietly resolves in favor of one system.

On the workflows your team runs most, the discrepancy is called out directly. Those are built to flag it, because the reconciliations a GC does every week are known and worth building for. Everywhere else, the source data is in front of you and the delta is a two-minute trace instead of an agenda item.