AI for engineering firms, tested on old billing cycles first.

Every active project gets an invoice every billing period, and at most firms a project manager reviews the draft before it goes out. Copies of a past cycle hold everything a fair test needs: the hours as charged, the expense reports, the subconsultant invoices, and the invoice the client actually received. Your reviewer, the colleague who knows this billing inside out, checks every draft against that invoice.

Proposals depend on what gets advertised and when. Billing comes due every period whether the month was busy or not. That makes it the job where a test on old documents looks most like the real work.

The math is rarely the hard part. One firm can bill hourly against a rate schedule on one contract, a fixed fee by phase on the next, and a percent of construction cost on a third. Deltek Ajera, for example, offers five billable billing types: Time & Expense, Fixed Fee, Percent Complete, Unit Price and Percent of Construction Cost. Each needs its own inputs and often its own invoice format, and public clients add progress reports and backup rules on top.

Ownership shapes the sign-off. Many engineering firms are employee-owned, so the person who approves a test like this is often a principal or the CFO rather than a founding family. And when a firm buys another, the acquired firm usually arrives with its own billing setup.