Plan from the supplied facts
Original plan has base effort 5 hours. Risk A adds 4 and risk B adds 6. The supplied scenario set permits neither, A only or B only, but expressly excludes both together. The maximum is therefore 11, not 15 hours. No probability is given.
| Permitted scenario | Added hours | Total hours |
|---|---|---|
| Neither | 0 | 5 |
| A only | 4 | 9 |
| B only | 6 | 11 |
Work through the choice
The dependency between risks changes the tail, even though each isolated addition stays the same. Adding maxima assumes a joint case the supplied model excludes.
If both together is added as a permitted scenario, what is the new maximum?
Show the worked answer
5+4+6=15 hours. The upper bound changes because the joint scenario changed, not because an individual risk estimate changed.
Material to use in your plan
Use one row per permitted joint scenario with base, additions and total. Record mutually exclusive risks explicitly before summing an effort envelope.