3-points-estimating
O = Optimistic, P = Pessimistic, M = Most likely or best guess (BG)
For Activity A:
o = 4 hours , m = 8 hours , p = 16 hours
Triangular Distribution:
E = (4 + 8 + 16 ) / 3
E = 28 / 3
E = 9.3 hours
Beta Distribution (PERT):
E = (4 + 4(8) + 16) / 6
E = 52 / 6
E = 8.7 hours
The Standard Deviation is a measure of variability from the mean and is defined as (p - o)/6 so in the example above
S.D = (16 - 4 )/6 = 12/6 = 2 hours
This means that using the normal distribution function where there is a 68% of the probability of one SD range from the mean It means that 68% chance of the schedule having a duration of 8.7+/-2 which is 6.7 to 10.7 hours
3-points-estimating
O = Optimistic, P = Pessimistic, M = Most likely or best guess (BG)
For Activity A:
o = 4 hours , m = 8 hours , p = 16 hours
Triangular Distribution:
E = (4 + 8 + 16 ) / 3
E = 28 / 3
E = 9.3 hours
Beta Distribution (PERT):
E = (4 + 4(8) + 16) / 6
E = 52 / 6
E = 8.7 hours
The Standard Deviation is a measure of variability from the mean and is defined as (p - o)/6 so in the example above
S.D = (16 - 4 )/6 = 12/6 = 2 hours
This means that using the normal distribution function where there is a 68% of the probability of one SD range from the mean It means that 68% chance of the schedule having a duration of 8.7+/-2 which is 6.7 to 10.7 hours