Plan from the supplied facts
Original fictional project has already spent 10 hours, unrecoverable in either option. Staying needs eight future hours. Switching needs three transition hours plus four remaining implementation hours. No other consequence is modelled. Compare future effort from the current decision point.
| Option | Historical h | Future h | Lifetime total h |
|---|---|---|---|
| Stay | 10 | 8 | 18 |
| Switch | 10 | 3 + 4 = 7 | 17 |
| Difference | 0 | 1 less for switch | 1 less for switch |
Work through the choice
Historical ten remains in both totals. Counting it only against switching would penalise that choice with effort already spent regardless of the new decision.
Which option needs less future effort in this model?
Show the worked answer
Switching: seven versus eight, one hour less. This effort result does not decide unmodelled disruption, risk or outcomes.
Material to use in your plan
Keep sunk effort as a shared historical row. List only avoidable future tasks, transition costs and retained work under each option, with other consequences beside the effort comparison.