General Motors is planning a new ad campaign targeted at aging Boomers who seek roominess, comfort and elegance.
Based on past experience, Task #1 usually takes days 52. If things do not go as planned, the task will take 74 days. If things go very well, Task #1 can be completed in 40 days.
Task #2 usually takes 87 days. Task #2 will be completed in 73 days if everything goes well. If there is a glitch, it will take 104 days. Normally, Task #2 cannot start until task #1 has been completed.
Task #3 normally takes 75 days under all conditions/scenarios. Task #3 cannot be started until task #2 has been completed.
Task #4 cannot start until Task #3 has been completed. Task #4 normally takes 72 days. For Task #4, the best and worst case scenarios are 64 days and 98 days, respectively.
Under normal circumstances, it takes 68 days to complete Task #5. The best and worst case scenarios are 53 and 71 days, respectively.
Task #6 normally takes 118 days. Under ideal conditions, it can be completed in 97 days. The pessimistic time estimate is 127 days. Task #6 cannot start until Task #4 is completed.
Questions:
- What is the expected number of days to complete this project.
- What is the variance for the project?
- What is the probability that the project will take more than 390 days to complete?