A project budget can appear complete while leaving the largest uncertainties hidden inside a single total. Before comparing revenue with cost, separate what has been quoted, what has been estimated and what is still undefined.
Build an assumption register
Create one row for each material cost or operating assumption. Record the source, date, scope, exclusions and person responsible for updating it. A contractor estimate, an equipment proposal and an owner's allowance should not appear equally certain merely because they occupy the same spreadsheet.
The SBA's planning resources include startup-cost preparation. For a property-based project, use a project-specific register to connect that planning work to land, site work, buildings, equipment, opening expenses and the operating ramp-up.
Check for scope gaps before adding contingency
Review whether estimates cover the same concept and quantities. Look for items that may sit between suppliers: installation, connections, delivery, site preparation or work needed before an equipment package can operate.
Keep contingency visible and explain its purpose. It should not substitute for identifying a known cost that has simply been omitted. Record pending information so the next revision can close specific gaps.
Test one change, then a combined scenario
First vary one uncertain assumption to understand its effect. Then examine a plausible combination, such as a later opening with slower initial activity. Avoid changing unrelated inputs merely to recover an attractive result.
An illustrative calculation can show the method without pretending to forecast a real project: if a specified cost item is assumed to be $100,000, a 10% increase adds $10,000 to that item. That arithmetic says nothing about whether 10% is a realistic scenario for the actual project; the scenario needs its own basis.
Make the output useful for a decision
Report which assumptions most affect the result and what information would reduce uncertainty. A good review may lead to revised scope, an updated quote, a different opening sequence or additional market work.
Bring the cost register, available proposals and project schedule to the feasibility study discussion. The aim is to understand the conditions behind the conclusion, not to make a spreadsheet produce a predetermined answer.