In ProgressChapter 3: Project Management

The critical path for the network activities shown below is _______ with duration _______.

B-C-E; 12 The sum of the duration for this network is 12 (4+6+2 = 12).

The EF of an activity is the:

ES + Activity time

The LS of an activity is the:

LF - Activity time

The critical path of a network is the__________

Longest time path through the network.

The three phases involved in the management of large projects are:

Planning, scheduling, and controlling

__________ is the amount of time an individual activity in a network can be delayed without delaying the entire project.

Slack Time

Dummy activities__________

are used when two activities have identical starting and ending events.

The Beta distribution is used in project management to _______.

calculate expected activity times

With respect to PERT and CPM, slack__________

is the amount of time a task may be delayed without changing the overall project completion time.

Which of the following is determined during the forward pass?

Early Start

Which of the following statements regarding Gantt charts is true?

Gantt charts are visual devices that show the duration of activities in a project.

Which of the following is a basic assumption of PERT?

No activity in the network must be repeated.

Which of the following statements regarding PERT analysis is true?

Only critical activities contribute to the project variances.

An activity on a PERT network has these time estimates: optimistic =2, most likely = 3, and pessimistic 8. Its expected time and variance (if it is a critical activity) are:

The expected time and variance (if it is a critical activity) are 3.67 and 1, respectively. Expected time (t) is calculated using the following formula: t = (a + 4m + b) / 6, where a = optimistic time estimate (in this case 2); m = most likely time estimate (in this case 3); and b = pessimistic time estimate (in this case 8). Therefore; t = (2 + 4*3 + 8) / 6 t = 22 / 6 t = 3.67 Variance (v) is calculated using the following formula: v = [(b-a) / 6]2, where b= pessimistic time estimate (in this case 8) and a = optimistic time estimate (in this case 2). Therefore; v = [(b-a) / 6]2 v = [(8-2) / 6]2 v = [6/6]2 v = [1]2 v = 1

An activity has an optimistic time of 15 days, a most likely time of 18 days, and a pessimistic time of 27 days. What is the expected time?

The expected time is 19 days. Expected time (t) is calculated using the following formula: t = (a + 4m + b)/6, where a = optimistic time estimate (in this case 15); m = most likely time estimate (in this case 18); and b = pessimistic time estimate (in this case 27). Therefore; t = (15 + 4*18 + 27)/6 t = 114/6 t = 19

An activity on a PERT network has these time estimates: optimistic = 2, most likely = 5, and pessimistic = 10. Its expected time is:

The expected time is 5.33. Expected time (t) is calculated using the following formula: t = (a + 4m + b)/6, where a = optimistic time estimate (in this case 2); m = most likely time estimate (in this case 5); and b = pessimistic time estimate (in this case 10). Therefore; t = (2 + 4*5 + 10)/6 t = 32/6 t = 5.33

A project's critical path is composed of activities A (variance .33), B (variance .67), C (variance .33), and D (variance .17). What is the standard deviation on the critical path?

The standard deviation on the critical path is 1.22. To calculate the standard deviation you take the square root (√) of the sum of the critical path activity variances. In this case, Standard deviation = √.33+.67+.33+.17 Standard deviation = √1.5 Standard deviation = 1.22

PERT analysis computes the variance of the total project completion time as:

The sum of the variances of all activities on the critical path.

WBS stands for which of the following project management tools?

Work Breakdown Structure

Which of these statements regarding time-cost tradeoffs in CPM networks is true?

Crashing shortens the project duration by assigning more resources to one or more of the critical tasks.

An activity has an optimistic time of 11 days, a most likely time of 15 days, and a pessimistic time of 23 days. What is its variance?

The variance for this activity is 4. Variance (v) is calculated by using the following formula: v = [(b-a) / 6]2, where b = pessimistic time estimate (in this case 23) and a = optimistic time estimate (in this case 11). Therefore: v = [(b-a) / 6]2 v = [(23-11) / 6]2 v = [12 / 6]2 v = [2]2 v = 4

An activity on a PERT network has these time estimates: optimistic = 1, most likely = 2, and pessimistic = 5. Its variance is:

The variance is 0.444. The variance is 0.444. Variance is calculated using the following formula: variance = [(b-a)/6]2, where a = optimistic time estimate (in this case 1) and b = pessimistic time estimate (in this case 5). Therefore; variance = [(5-1)/6]2 = 0.444

A simple CPM network has five activities, A, B, C, D, and E. A is an immediate predecessor of C and of D. B is also an immediate predecessor of C and of D. C and D are both immediate predecessors of E. Given the above scenario, which of the following is correct?

There are four paths in this network. The four paths are A-C-E, A-D-E; B-C-E, B-D-E.

In a PERT network, non-critical activities that have little slack need to be monitored closely__________

because near-critical paths could become critical paths with small delays in these activities