A revised estimate of £1.07 million is not very informative if the previous estimate was £1 million and the only explanation is “design development”. The £70,000 movement may contain several different decisions.
In the example shown, additional scope adds £60,000, a quantity correction removes £15,000 and revised rates add £25,000. Those movements reconcile exactly to the new total, but they have different implications for the project.
The scope addition may need a client decision. The quantity correction may require a review of the measurement process. The rate revision may reflect a new quotation or a changed procurement assumption.
| Movement | GBP |
|---|---|
| Previous estimate | 1,000,000 |
| Additional scope | 60,000 |
| Quantity correction | −15,000 |
| Rate revision | 25,000 |
| Revised estimate | 1,070,000 |
An original worked example. Each movement is classified once and reconciles to the revised total.
Agree the categories before the review
A small set of consistent movement categories is usually enough. What matters is that each change appears once and has a reference back to the affected item.
Do not use reconciliation as a way to disguise corrections. If the earlier estimate omitted something that was already in scope, describe the correction honestly. The team can then decide whether another check is needed elsewhere.
Where several changes affect the same item, choose a consistent calculation order and explain it. Otherwise quantity and rate effects can be allocated differently by different reviewers even when they agree on the final amount.
The reconciliation should leave the decision maker with an account of why the estimate moved and which parts require action. That is more valuable than a coloured percentage beside the new total.