Overbilling hides between pay applications

Ask any experienced project accountant what actually slips through review and they won't say arithmetic. They'll say the line that's been quietly billing a little ahead of its physical progress for three months, or the sub whose cumulative draw has crept past its scheduled value while every individual application looked reasonable.

Why single-document review misses it

A pay application is a snapshot. Overbilling is a trend. A line billed at 34% this month is fine - unless it was billed at 31% last month against work that hasn't moved, or unless 34% puts the cumulative total over 100% of the scheduled value once you add the stored materials. None of that is visible in the document on your desk. It's only visible against the prior applications, which is precisely the context a spreadsheet reviewer has to reconstruct by hand every single month.

Cross-application cumulative tracking catches what a single pay app structurally cannot show. In practice we see line items creeping from 63% to 71% to 79% across three months of an earthwork line that's been stalled since month one.

What the machine is good at

This is the kind of check computers were made for: keep a running, per-line cumulative ledger across every application in a project's life, compare each new draw against it, and flag the moment a line's to-date exceeds its scheduled value or its progress outpaces reality. It's not judgment - it's memory and arithmetic at a scale humans can't hold. The reviewer still decides what to do about it. The machine just makes sure they never miss it.