Acquisition and owner oversight · Field guide · October 9, 2026
Maintain an acquisition assumption register
Every purchase model contains facts, estimates and open questions. An assumption register separates them so a confident spreadsheet does not hide uncertain inputs. Give material assumptions an evidence source and an expiry or recheck date. The register complements the financial model rather than replacing professional diligence.
Evidence to assemble
Gather the source records before completing the worksheet. A missing record should remain an open question. Keep the original alongside any summary so the next person can trace the decision.
| Input | Record with it |
|---|---|
| Current purchase model | Record the source, document date, reviewer and unresolved question. |
| Seller document list | Record the source, document date, reviewer and unresolved question. |
| Written operating quotes | Record the source, document date, reviewer and unresolved question. |
| Open diligence questions | Record the source, document date, reviewer and unresolved question. |
Work through the decision
- Label each input as observed, quoted or assumed.
- Record source and document date.
- Identify which decision depends on the input.
- Update the model when evidence changes.
For each action, name the person responsible for preparing the response and the person who approves it. Record what evidence would close the item. If new information changes cost, timing or scope, update the affected plan and identify who needs the revised version.
Common failure to avoid
Do not replace an assumption with a new number without retaining its history. Otherwise an apparent improvement in the model can be difficult to explain.
Worked example
An illustrative operating model uses a placeholder utility allowance. A complete year of bills later arrives and shows higher seasonal costs. The register preserves the original allowance, links the bills and identifies who must update the budget before the owner reviews it.
This is an illustrative workflow, not a client case study or a forecast. Replace the example’s facts with the records for your own project.
Complete your planning worksheet
Use the fields to connect evidence, action and approval. Your entries stay in this page and are included only when you choose to download them. They are not sent to a server and are not saved after a page reload.
Close the handoff
A finished worksheet should identify the result, its evidence and any remaining owner. If the result is uncertain, record the next action instead of marking the whole task complete. Keep the worksheet with the relevant source file and tell the receiving person which version applies.