By role / Cost controller
Two guides tell you how to build the number. Neither follows it past handover.
The GAO cost and schedule guides are the most complete free statements of what a defensible estimate and a defensible schedule look like. Both are about a project, and a project ends.
You own the estimate, the baseline and the forecast, and you are asked every month whether the number is still good. The honest answer depends on things that are not in your cost system.
Standards governing your work
GAO Cost Estimating and Assessment Guide, GAO-20-195G, March 2020, free in full
Four characteristics of a reliable estimate, comprehensive, well documented, accurate and credible, and a twelve-step process for producing one. It is unusually explicit that an estimate without a documented basis is not an estimate, which is the part most often skipped.
GAO Schedule Assessment Guide, GAO-16-89G, December 2015, free in full
Ten best practices for a schedule that can carry a forecast, including capturing all activities, sequencing them, establishing the critical path and conducting a schedule risk analysis. The test it applies is whether the schedule can be used to predict, not whether it can be used to report.
ICMS 3, International Cost Management Standard, free in full with its Basis for Conclusions, agreed by 49 professional bodies
A classification and presentation structure for life cycle costs and carbon, so that construction, renewal, operation, maintenance and end-of-life costs are reported in comparable categories. It settles how costs are grouped and reported. It does not undertake to control them.
Read the sources
- GAO Cost Estimating and Assessment Guide, GAO-20-195G, March 2020GAO-20-195G, March 2020; read 2026-08-24.
- GAO Schedule Assessment Guide, GAO-16-89G, December 2015GAO-16-89G, December 2015; read 2026-09-01.
- ICMS 3, International Cost Management Standard, life cycle costs and carbonthird edition, 2021; read 2026-08-29.Free. Agreed by 49 professional bodies through the ICMS Coalition, which RICS convenes.
- ICMS 3 Basis for ConclusionsDecember 2021; read 2026-08-29.Free. The coalition stating why the standard says what it says, which ISO does not publish.
Where that stops
The two GAO guides are project instruments and stop at the end of the project. ICMS 3 covers the whole life and is a classification standard: it tells you how to structure and present the cost, not how to hold it. Between them sits the question you will actually be asked, which is whether the money being spent this month is buying the thing the operating budget was set for. Nobody’s standard owns that join, so the material below is arranged across it rather than either side of it.
Whether the estimate is a measure of the cost or a measure of how little is yet known, and whether the whole-life figure beside it rests on anything.
What to examine
- Definition maturity and the estimate
Does the estimate state the class it was produced at, and does that class match the scope definition actually achieved?
- Whole-life cost and the operating consequence
Has the cost of owning this asset been estimated by, or at least shown to, the people who will have to pay it?
Instruments
- Lifecycle cost sensitivity
Take three real costed buildings and watch the construction share of lifecycle cost move from 66% to 7% while the data stays exactly the same.
Whether the variance you are reporting is against a baseline that has held, and whether the forecast has ever moved for a reason.
What to examine
- Baseline integrity
Is the baseline currently being reported against the one that was sanctioned, and if not, is every step between the two documented?
- Change, planned and unplanned
Are changes assessed before they are made, and does anyone examine changes that were made without being assessed?
- Forecast credibility
Does the forecast reflect what is now known, or does it reflect what was committed?
Instruments
- Earned value calculator
From planned value, earned value and actual cost, the variances and indices; add the budget at completion for the estimates at completion. Formulas shown and cited.
- Reporting history check
It does not ask whether the project is healthy. It asks whether the reporting on it has ever produced a signal, across the whole history rather than this month.
- Payment chain calculator
Add up the payment periods in the rule that governs your contract, in the unit the rule is written in, and see the wait in calendar days and what financing it costs on every certificate.
- What a technical point is worth
Take the quality and price split your tender already publishes and see what it commits you to pay for one technical point, the lead no price can close, and the penalty a mid-range bid carries.
Related writing
- Every programme performs well against a baseline it can move
- A forecast that never moves is not stable, it is unexamined
- Your contingency and their contingency are different money
- Moving a date is not the same as re-planning
- The critical path cannot show a delay nobody scheduled
- The ground was always there. The record was not.
- Private projects overrun too. The difference is who counts.
- The payment chain is a loan, and the contractor is the lender
- Every award rule makes you publish the weighting. None makes you defend it.
- An extension of time is tested against records made during the delay
Whether the cost you are closing out becomes an asset value somebody else can defend, and which clocks start on the date you certify.
What to examine
- Taking over, and what was waived to achieve it
Were the contractual conditions for taking over actually met, and where they were not, who agreed to proceed and on what record?
Instruments
- What follows the certificate, and when
Enter one completion date and get every consequential date under your contract regime, each computed from the clause that sets it.
- Componentisation calculator
One building, two treatments the same manual permits, and the gap between the annual charges they produce.
Whether the renewal profile the entity is about to commit to is a forecast or a straight line, and what the assumption behind it is worth.
What to examine
- Alignment of the financial and technical view
Do the finance function and the engineering function describe the same asset base in terms that reconcile?
Instruments
- Renewal profile
Read your own register in this page and see when items fall due for renewal, first with every item on a single life and then with lives spread around it.
- Three lives for the same asset
The accounting life, the observed service life and the design life of one item, side by side, with what the difference between them costs a year.
- Criticality screen
Find the assets that have to be looked at separately, and see what a likelihood times consequence ranking does to that list.
In the asset lifecycle method
This page composes material published elsewhere on this site and adds no claim of its own. The arrangement into stages is this publication’s, as the framework says at length; the requirements above are quoted from documents that are free to read and linked next to each. Where a stage is empty for this role, it says so rather than being left out.