Question

4. A project has the following tasks and duration estimates given. These three tasks are done in succession on a project. Task Optimistic Estimate Most Likely Estimate Pessimistic Estimate Alpha 30 days 40 days 50 days Beta 20 days 25 days 28 days Charlie 4 days 10 days 12 days Delta 25 days 30 days 50 days

a. What is the expected duration for the project? (3 points)

b. What is the variance for the project? (3 points) .

c. What is the standard deviation of the project? (3 points)

d. What is the range of the duration of the project given 3 sigma? (3 points)

Answer 1

Based on the given data, we tabulate as shown below:

Based on above,

a. The expected duration for the project

As seen from above, the expected duration of the project is 106.5 days

The above table in form of formulas is shown below for better understanding and reference:

b. The variance for the project

As seen from above, the expected duration of the project is 32.03 days

The above table in form of formulas is shown below for better understanding and reference:

c. The standard deviation of the project

Standard Deviation of the project = = = 5.66

d. The range of the duration of the project given 3 sigma

For 3 sigma, the probability = 99.87%

For probability = 99.87%, z value = 0.9987

0.9987 =

Required Duration = 112.15 days