Module 24 Terms

Question 1

one point estimate

Answer 1

Using the deterministic approach requires that the team expert provide a reliable estimate of the time necessary to complete the activity. This method is also called the one-point estimate method because the expert provides a single estimate for an activity based on either his or her own knowledge or historical information.

Question 2

triangular distribution

Answer 2

The first probabilistic approach is the triangular distribution or simple average. The three estimates are averaged together.

Question 3

beta distribution

Answer 3

The beta distribution still uses the three estimates (optimistic, most likely, and pessimistic) but places emphasis on the most likely estimate.

The beta distribution method was developed as the project evaluation and review technique (PERT).

Question 4

standard deviation

Answer 4

The standard deviation is a statistical measure of how much the actual activity duration is likely to vary.

We will consider an example using the same three estimates from the triangular distribution:

Optimistic Estimate = 15 days

Most Likely Estimate = 20 days

Pessimistic Estimate = 35 days

Base on the beta distribution, the activity duration estimate would be 21.67 or 22 days (rounded).

Question 5

deterministic estimate

Answer 5

Activity durations are best developed by the team members who will be involved in the later execution of the activities. These estimates can be single-point estimates, which are often called “deterministic estimates.”

Question 6

probabilistic estimate

Answer 6

Probabilistic duration estimation techniques are used when there is uncertainty in how long an activity will take.

Probabilistic approaches use basic statistics to account for uncertainty in activity duration estimates.

The first probabilistic approach is the triangular distribution or simple average. The three estimates are averaged together.

The second probabilistic method is the beta distribution or weighted average. The beta distribution still uses the three estimates (optimistic, most likely, and pessimistic) but places emphasis on the most likely estimate.

Question 7

learning curve

Answer 7

The concept of learning curves suggests that as a person repeats a task, the time required to complete the task decreases.