Contingency time: a time buffer the schedule owns, how big and where it sits
The greenhouse schedule appears to carry spare time, but the manager cannot identify whether it is deliberate contingency or a result of the current logic. When a delivery moves, one planner shifts the milestone and another says the reserve has paid for it. The team needs one agreed representation and a record of what was actually used.
Make a deliberate time reserve identifiable, justified and governed within the actual schedule. Explain which uncertainties it addresses and how its use will be reported. Do not infer an authorized reserve from a float number or conceal the same allowance inside several activities. This is an original planning routine; the reserve does not establish entitlement, assign ownership of contractual float or guarantee a protected completion date.
Connect the allowance to risks and recorded use
- Define what the reserve is for. Identify the protected commitment, relevant risk assumptions and available project evidence. Note correlations, missing information and the range of plausible effects. Do not add every worst-case delay together without examining the sequence or set a universal percentage. Record the reasoning and who will reconsider it when the evidence changes.
- Agree the schedule representation. With the responsible scheduler and project decision-makers, show where the allowance sits and how it interacts with actual dependencies and calendars. A clearly named buffer activity may suit the agreed method, but it is not compulsory for every schedule. Keep other allowances identifiable so the same uncertainty is not counted twice.
- Define who can authorize and record use. Agree what triggers a drawdown request, what supporting update is needed and who decides. Record the event, amount used and remaining reserve without hiding the actual delay. Distinguish using contingency from changing scope, sequence, dates or obligations; those decisions retain their own applicable approval process.
- Review remaining exposure as well as remaining days. Compare the current reserve with unresolved risks, changed readiness and upcoming commitments. Explain whether a previously assumed response is still available. A small balance after risks have reduced means something different from the same balance before several remain. Report limits and needed decisions, not just a green milestone.
Common mistakes
- Treating any displayed float as authorized contingency.
- Counting the same uncertainty in several allowances.
- Drawing down a reserve without preserving the actual event.
- Reporting the balance without the risks still exposed.
Checklist
A usable time reserve records
- Protected commitment and stated risk rationale.
- Agreed representation, dependencies and calendar.
- Other allowances and possible double counting.
- Drawdown authority, evidence and remaining balance.
- Current exposure and the next review decision.
Check your understanding
Ten working days of reserve have a recorded three-day use. What can the remaining seven days tell the manager?
