There are ten tasks in a project and they all need to be completed within their estimate for the project to be delivered on time. Each task has a 10% chance that is mis-estimated and will take longer.
If a task has a 10% chance of being late it has a 90% (0.9) probability of success. Probability of multiple events is calculated by multiplying all the probabilties: 0.9 * 0.9 * 0.9 etc. In the contrived example where all probabilites are the same we can do a simple power of:
Eshell V5.10.2 (abort with ^G)
1> math:pow(0.9, 10).
0.3486784401000001The total probability of the project being delivered on is 34.8%, pretty bad eh?
