Committed Cost vs. Actual Cost vs. Forecast: The Three Numbers PMs Confuse

Three numbers, three different questions

Most cost disputes inside a company are really vocabulary problems. Someone says the job has spent 600,000 dollars, someone else says it is at 750,000, and a third person says it will finish at 900,000. All three can be right, because they are answering three different questions.

Sort it out once and the confusion goes away: actual cost answers what have we spent, committed cost answers what have we promised to spend, and forecast answers what will we spend in total. Each is useful, and none of them substitutes for the others.

Defining each one cleanly

A clean way to think about the relationship: committed cost gradually converts into actual cost as invoices arrive. The day you sign a 200,000 dollar subcontract, that is 200,000 committed and zero actual. As the sub bills, the committed number shrinks and the actual number grows, but the total obligation was always there.

• •Actual cost — costs that have actually been incurred and booked: labor run through payroll, supplier invoices received, equipment time posted. This is the most concrete number and also the most backward-looking.
• •Committed cost — the value of subcontracts and purchase orders you have issued but not yet been invoiced for. The dollars are obligated by a signed document even though no invoice has arrived. Open commitment is committed cost minus what has been invoiced against it so far.
• •Forecast (projected final cost / EAC) — your best estimate of total cost at completion: actual cost to date plus your estimate of the cost still to come. It is the only number that looks forward.

Why ignoring committed cost flatters the job

Here is the trap. Say a code has a 250,000 dollar revised budget. You have received 90,000 dollars of invoices, so actual cost is 90,000. Looking only at actuals, you have 160,000 dollars of room and feel comfortable.

But you also signed a subcontract for 220,000 dollars to do that scope, and the sub has only billed the 90,000 so far. Open commitment is 130,000 dollars. Add committed to actual and you are at 220,000 against a 250,000 budget — only 30,000 of real room, not 160,000. Read actuals alone and you would happily approve another 100,000 of spend that does not exist.

This is exactly how a job that is actually tight gets reported as healthy for months. The invoices simply have not caught up to the commitments yet. By the time the actuals arrive, the overrun is already locked in by signed contracts you cannot unsign.

How to read the three together

Field PM keeps these separate by design: it pulls committed cost from issued POs and subcontracts, actuals from time and approved invoices, and rolls both into a projected final, so the PM dashboard shows true consumption against budget instead of a flattering actuals-only view.

• •Track actual plus open commitment as your true cost consumed. That is the number to compare against the revised budget for any code with subcontracts or POs.
• •On self-perform labor codes, committed cost is usually near zero — there is no PO for your own crew — so the live signal there is actual versus forecast, driven by productivity.
• •Never let forecast fall below actual plus open commitment. If your projected final is less than what you have already spent and obligated, the forecast is wrong by definition.
• •When a commitment is issued, the forecast should already reflect it. Signing a subcontract above budget is a fade the moment the ink dries, not when the sub bills.

A quick gut check before any cost meeting

Before you walk into a cost review, run one sentence in your head for each problem code: we have spent X, we are obligated for another Y, and we believe it finishes at Z against a budget of B. If you cannot fill in all four numbers, you do not understand the code yet.

When X plus Y is already crowding B, the conversation is about damage control. When Z is comfortably under B and X plus Y supports it, the code is genuinely fine. The discipline of always stating all four keeps anyone from hiding behind the friendliest number.