Estimation Techniques

Correct Answer: 46.67 days

The PERT (Program Evaluation and Review Technique) estimate for a project is calculated using the formula: PERT estimate = (Optimistic time + 4 * Most likely time + Pessimistic time) / 6 Given the optimistic time is 30 days, the pessimistic time is 70 days, and the most likely time is 45 days, we can plug these values into the formula: PERT estimate = (30 + 4 * 45 + 70) / 6 Calculating this step by step: First, calculate 4 * 45, which is 180 Then add 30 to 180 to get 210 Add 70 to 210 to get 280 Finally, divide 280 by 6 This results in a PERT estimate of 46.67 days

Correct Answer: 10.67 weeks

In PERT (Program Evaluation and Review Technique) estimate, the expected timeline is calculated by the formula: (optimistic + 4*most likely + pessimistic) divided by 6. Substituting the given values (8 + 4*10 + 16) / 6 gives us approximately 10.67 weeks. Therefore, the answer of 12 weeks is incorrect, as it appears to be the average of the optimistic, most likely and pessimistic estimates without considering the weighted approach of PERT. The answer of 11.5 weeks seems to be a simple average of the most likely and pessimistic estimates, which also doesn't reflect the PERT method. The answer of 9 weeks doesn't fit into any known estimate calculation method for this scenario.

Correct Answer: It is weighted four times more heavily than the others

In a PERT (Program Evaluation and Review Technique) estimate, the 'most likely' time estimate is indeed weighted four times more heavily than the optimistic and pessimistic estimates. This weighting is a key feature of the PERT formula. The PERT formula for calculating the expected time (E) is: E = (O + 4M + P) / 6 Where: O = Optimistic estimate M = Most likely estimate P = Pessimistic estimate As we can see from this formula, the most likely estimate (M) is multiplied by 4, while the optimistic and pessimistic estimates are only counted once each. This gives the most likely estimate significantly more influence on the final expected time. This weighting reflects the assumption that the most likely estimate is generally the most accurate and should have the greatest impact on the overall time estimate. The optimistic and pessimistic estimates are included to account for best-case and worst-case scenarios, but they are given less weight as they are considered less probable. The other options are incorrect: - Equal weighting would not accurately represent the higher probability of the most likely estimate occurring. - Using the median would not take into account the relative probabilities of each estimate. - Weighting the most likely estimate twice as much would undervalue its significance in the PERT calculation.