Project Management CHAPTER 13

Project ManagementCHAPTER 13

TRUE/FALSE

13.1PERT and CPM are quantitative analysis tools designed to schedule and control large projects.

13.2PERT is a deterministic analysis tool allowing for precise times of activities within a project.

13.3PERT had its beginnings in a military department of the United States.

13.4CPM is a probabilistic analysis of managing a project.

13.5An event is a point in time that marks the beginning or ending of an activity.

13.6A network is a graphical display of a project that contains both activities and events.

13.7The optimistic time is the greatest amount of time that could be required to complete an activity.

13.8PERT is a network technique similar to CPM, but PERT allows for project crashing.

13.9The most likely completion time of an activity is used to represent that activity’s time within a project.

13.10The expected completion time and variance of an activity is approximated by the normal distribution in a PERT analysis.

13.11PERT was developed for a project for which activity or task times were uncertain.

13.12CPM was developed for use in managing projects which are repeated and about which we have good information as to activity or task completion times.

13.13With PERT, we are able to calculate the probability of finishing the project on a particular day.

13.14With CPM, we are able to calculate the probability of finishing the project on a particular day.

13.15A PERT or CPM network shows activities and activity sequences.

13.16One of the most difficult aspects of using PERT is defining the activities so that they have measurable/observable starts and finishes.

13.17Before drawing a PERT or CPM network, we must identify each activity and their predecessors.

13.18The three time estimates employed in PERT are: optimistic time, average time, and pessimistic time.

13.19In the PERT process, if an activity has zero variance it must be on the critical path.

13.20Given the variability of the activity completion time, the original critical path we identify in our PERT analysis may not always be the actual critical path as the project takes place.

13.21In PERT, the activity completion times are modeled using the beta distribution.

13.22In PERT, the earliest finish time in one activity will always be the earliest start time of the following activity.

13.23In PERT, the earliest start time for an activity is equal to the latest of the earliest finish times of all of its immediate predecessors.

13.24One of the limiting assumptions of PERT is that for any activity to start, all of its immediate predecessors must be complete.

13.25One of the limiting assumptions of PERT is that all activities must be completed at some time during the project.

13.26One of the most significant benefits of PERT is that it forces the project manager to sit down and plan the project in great detail – and thus come to an understanding of relationships between the activities.

13.27Slack is the time an activity can be delayed without impacting the completion time of the project.

13.28It is never possible to delay an activity without impacting the project completion time.

13.29The variance of the project completion time is equal to the sum of the variances of all the activities.

13.30In PERT, we assume that the project completion time can be modeled by the normal distribution.

13.31One PERT/COST assumption is that money is spent at a constant rate over the time taken to complete an activity.

13.32PERT helps the project manager understand both which activities must take place and which funds must be expended.

13.33A limitation of PERT/COST is the assumption that money is spent at a constant rate over the time taken to complete the project.

13.34In CPM, we assume that the cost to complete the task is a linear function of the time to complete the task.

13.35In CPM, crashing an activity which is not on the critical path increases the cost of the project.

13.36In CPM, if we are going to crash an activity, we should crash it to the maximum extent possible.

*13.37In CPM, crashing an activity which is not on the critical path reduces the cost of the project just as much as crashing one on the critical path.

*13.38One of the drawbacks to using either CPM or PERT to manage an actual project is the amount of data that must be collected over the life of the project to implement either method.

*13.39In PERT, the variance in completion time is equal to the variance of the most time consuming activity on the critical path.

*13.40Given the assumptions in PERT, the probability that a project will be completed in less time than required by the activities on the critical path is approximately 50%.

*13.41One should always wait until an activity’s latest start time before commencing the activity.

*13.42Using PERT/COST, one is able to complete the project for less money than using PERT alone.

*13.43If an activity has 4 days of slack, and we delay it 2 days, the project will also be delayed two days.

*13.44Gantt and PERT charts provide the same information, just in different formats.

*13.45Gantt charts contain information as to the time taken by each activity, but not the sequential dependencies of the activities.

*13.46Using PERT/COST as a management tool, it is always possible to bring a project in under budget.

MULTIPLE CHOICE

13.47The critical path of a network is the

(a)shortest time path through the network.

(b)path with the fewest activities.

(c)path with the most activities.

(d)longest time path through the network.

(e)none of the above

13.48In a PERT network, the earliest (activity) start time is the

(a)earliest time that an activity can be finished without delaying the entire project.

(b)latest time that an activity can be started without delaying the entire project.

(c)earliest time that an activity can start without violation of precedence requirements.

(d)latest time that an activity can be finished without delaying the entire project.

(e)none of the above

13.49Slack time in a network is the

(a)time consuming job or task that is a key subpart of the total project.

(b)shortest amount of time that could be required to complete the activity.

(c)amount of time that you would expect it would take to complete the activity.

(d)amount of time that an activity can be delayed without delaying the entire project.

(e)none of the above

13.50A network activity is a

(a)point in time that marks the beginning or ending of an activity.

(b)time consuming job that is a subpart of the total project.

(c)graphical display of a project.

(d)network technique that allows three time estimates for each activity in a project.

(e)the longest time path through the network.

13.51Which of the following is not a concept associated with CPM?

(a)normal time

(b)probability

(c)normal cost

(d)crash cost

(e)deterministic network

13.52PERT

(a)assumes we do not know ahead of time what activities must be completed.

(b)allows computation of the program’s evaluation.

(c)is a network technique that uses three time estimates for each activity in a project.

(d)is a deterministic network technique that allows for project crashing.

(e)none of the above

13.53CPM

(a)assumes we do not know ahead of time what activities must be completed.

(b)is opposite to that of PERT, as it does not consider the network activities.

(c)is a network technique that allows three time estimates for each activity in a project.

(d)is a deterministic network technique that allows for project crashing.

(e)none of the above

13.54Managers use the network analysis of PERT and CPM to help them

(a)derive flexibility by identifying noncritical activities.

(b)replan, reschedule, and reallocate resources such as manpower and finances.

(c)plan, schedule, monitor, and control large and complex projects.

(d)all of the above

13.55In contrast to PERT or PERT/cost, CPM

(a)is a deterministic network model.

(b)uses crash times and costs.

(c)allows for calculating the least additional cost for shortening the project time.

(d)assumes that the activity times and costs are known with certainty.

(e)all of the above

13.56The expected time in PERT is

(a)a weighted average of the most optimistic time, most pessimistic time, and four times the most likely time.

(b)the modal time of a beta distribution.

(c)a simple average of the most optimistic, most likely, and most pessimistic times.

(d)the square root of the sum of the variances of the activities on the critical path.

(e)none of the above

13.57Given the following activity’s optimistic, most likely, and pessimistic time estimates of 4, 5, and 12 days, respectively, compute the PERT time for this activity.

(a)5

(b)6

(d)12

(e)none of the above

13.58Given the following activity’s optimistic, most likely, and pessimistic time estimates of 3, 3, and 9 days, respectively, compute the PERT time for this activity.

(a)3

(b)4

(d)9

(e)none of the above

13.59Given the following activity’s optimistic, most likely, and pessimistic time estimates of 4, 8, and 18 days, respectively, compute the PERT time for this activity.

(a)4

(b)8

(d)18

(e)none of the above

13.60Given the following activity’s optimistic, most likely, and pessimistic time estimates of 2, 10, and 20 days, respectively, compute the PERT variance for this activity.

(a)3

(b)6

(d)18

(e)none of the above

13.61Given the following activity’s optimistic, most likely, and pessimistic time estimates of 4, 12, and 18 days, respectively, compute the PERT variance for this activity.

(a)2.33

(b) 5.44

(d)64.00

(e)none of the above

13.62Given an activity’s optimistic, most likely and pessimistic time estimates of 3, 5, and 15 days, respectively, compute the PERT standard deviation for this activity.

(a)2

(b)4

(d)15

(e)none of the above

13.63Given the following small project, the critical path is ______days.

Activity / Immediate
Predecessor / Time
(days)
A / - / 10
B / - / 4
C / A, B / 6

(a)10

(b)14

(d)20

(e)none of the above

13.64Given the following small project, the critical path is ______days.

Activity / Immediate
Predecessor / Time
(days)
A / - / 8
B / A / 4
C / - / 10

(a)4

(b)10

(d)22

(e)none of the above

The following table provides information for questions 13.65 to 13.68.

Table 13-1
The following represents a project with known activity times. All times are in weeks.
Activity / Immediate
Predecessor / Time
A / - / 4
B / - / 3
C / A / 2
D / B / 7
E / C, D / 4
F / B / 5

13.65Using the data in Table 13-1, what is the minimum possible time required for completing the project?

(a)8

(b)14

(d)10

(e)none of the above

13.66Using the data in Table 13-1, what is the latest possible time that C may be started without delaying completion of the project?

(a)0

(b)4

(d)10

(e)none of the above

13.67According to Table 13-1, compute the slack time for activity D.

(a)0

(b)5

(d)6

(e)none of the above

13.68Using the data in Table 13-1, compute the latest finish time for activity E.

(a)4

(b)10

(d)25

(e)none of the above

The following table provides information for questions 13.69 to 13.72.

Table 13-2
The following represents a project with four activities. All times are in weeks.
Activity / Immediate
Predecessor / Optimistic
Time / Most
Likely
Time / Pessimistic
Time
A / - / 2 / 8 / 14
B / - / 8 / 8 / 8
C / A / 6 / 9 / 18
D / B / 5 / 11 / 17

13.69According to the data in Table 13-2, what is the critical path?

(a)A, B

(b)A, C

(c)B, D

(d)A, B, C, D

(e)none of the above

13.70According to the data in Table 13-2, what is the minimum expected completion time for the project?

(a)18

(b)19

(d)11

(e)none of the above

13.71According to Table 13-2, there are four activities in the project. Assume the normal distribution is appropriate to use to determine the probability of finishing by a particular time. If you wished to find the probability of finishing the project in 20 weeks or less, it would be necessary to find the variance and then the standard deviation to be used with the normal distribution. What variance would be used?

(a)2

(b)4

(d)12

(e)none of the above

13.72According to Table 13-2, there are four activities in the project. Assume the normal distribution is appropriate to use to determine the probability of finishing by a particular time. What is the probability that the project is finished in 16 weeks or less (round to two decimals)?

(a)0.07

(b)0.93

(d)0.77

(e)none of the above

13.73Consider a project that has an expected completion time of 60 weeks and a standard deviation of five weeks. What is the probability that the project is finished in 70 weeks or less (round to two decimals)?

(a)0.98

(b)0.48

(d)0.02

(e)none of the above

13.74Your company is considering submitting a bid on a major project. You determine that the expected completion time is 100 weeks and the standard deviation is 10 weeks. It is assumed that the normal distribution applies. You wish to set the due date for the project such that there is an 85 percent chance that the project will be finished by this time. What due date should be set?

(a)108.0

(b)110.4

(d)85.0

(e)none of the above

The following table provides information for questions 13.75 to 13.76.

Table 13-3
Activity / Immediate
Predecessor / Time / ES / EF / LS / LF
A / - / 4 / 0 / 4 / 6 / 10
B / - / 5 / 0 / 5 / 0 / 5
C / A / 3 / 4 / 7 / 10 / 13
D / B / 8 / 5 / 13 / 5 / 13
E / B / 3 / 5 / 8 / 14 / 17
F / C, D / 2 / 13 / 15 / 15 / 17
G / C, D / 6 / 13 / 19 / 13 / 19
H / E, F / 2 / 15 / 17 / 17 / 19

13.75According to Table 13-3, there are eight activities to be completed in a project with known activity times. How long could activity E be delayed without delaying the completion of the project?

(a)3

(b)9

(d)17

(e)none of the above

13.76According to Table 13-3, there are eight activities to be completed in a project with known activity times. What is the minimum possible time required for completing the project?

(a)13

(b)15

(d)19

(e)33

The following table provides information for questions 13.77 to 13.79.

Table 13-4
Activity / Immediate
Predecessor / Optimistic / Most
Likely / Pessimistic / Average / Standard
Deviation / Variance
A / - / 4 / 5 / 6 / 5 / 0.333 / 0.111
B / - / 2 / 5 / 8 / 5 / 1.000 / 1.000
C / A / 2 / 8 / 14 / 8 / 2.000 / 4.000
D / A / 5 / 5 / 5 / 5 / 0.000 / 0.000
E / B, C / 6 / 7 / 8 / 7 / 0.333 / 0.111

13.77According to Table 13-4, there are five activities in a PERT project. Which activities are on the critical path?

(a)A,B,C,D,E

(b)A,C,E

(c)B,D

(d)A,B,C,D

(e)none of the above

13.78According to Table 13-4, there are five activities in a PERT project. What is the variance of the critical path?

(a)5.222

(b)4.222

(d)0

(e)none of the above

13.79According to Table 13-4, there are five activities in a PERT project. If the normal distribution were used to find the probability of finishing this project in 24 weeks or less, what mean and variance would be used?

(a)20 and 4.222

(b)30 and 5.222

(d)30 and 4.222

(e)none of the above

13.80The critical path of a network is the

(a)path with the least variance.

(b)path with zero slack.

(c)path with the most activities.

(d)path with the largest variance.

(e)none of the above

13.81In a PERT network, the latest (activity) start time is the

(a)earliest time that an activity can be finished without delaying the entire project.

(b)latest time that an activity can be started without delaying the entire project.

(c)earliest time that an activity can start without violation of precedence requirements.

(d)latest time that an activity can be finished without delaying the entire project.

(e)none of the above

13.82Slack time in a network is the

(a)time consuming job or task that is a key subpart of the total project.

(b)shortest amount of time that could be required to complete the activity.

(c)amount of time that you would expect it would take to complete the activity.

(d)amount of time that an activity can be delayed without delaying the project.

(e)none of the above

13.83To do a PERT analysis of a project,

(a)we must know the sequence in which tasks are to be performed.

(b)we must know the number of tasks in the project.

(c)we must know the time estimates for each activity.

(d)we must compute an expected time for each activity.

(e)all of the above

13.84For which of the following projects are we more likely to use PERT than CPM as a management tool?

(a)performing maintenance in a chemical plant

(b)building a new hotel complex

(c)developing a new space vehicle

(d)constructing a new factory

(e)building a new highway

13.85PERT

(a)assumes we do not know ahead of time the specific amount of time an activity will require.

(b)allows time/cost trade-offs.

(c)is a probabilistic network technique that allows for project crashing.

(d)is a deterministic network technique that allows for project crashing.

(e)none of the above

13.86In PERT,

(a)an activity may not start until all activities scheduled for an earlier time have finished.

(b)we can have no more than two activities taking place simultaneously.

(c)after the project has begun, it is possible for a path other than the original critical path to become critical.

(d)we assume that the time to complete an activity is described by the normal distribution.

(e)none of the above

13.87Which of the following is incorrect? In PERT,

(a)we assume that all activities are completed.

(b)an activity may not start until all activities scheduled for an earlier time have finished.

(c)we assume that all activities have definable start and end points.

(d)we assume that the time to complete an activity is described by the beta distribution.

(e)none of the above

13.88In PERT, we assume that

(a)the times to complete individual activities are known with certainty.

(b)all activities are carried out by staff from our own organization.

(c)the total cost of a project is independent of the time to complete the project.

(d)the total time to complete all activities on the critical path is described by a normal distribution.

(e)none of the above

13.89CPM

(a)assumes that we know ahead of time all activities which must be completed.

(b)assumes that we may obtain additional resources or move existing resources from one activity to another.

(c)is an important technique when we are planning a project similar to projects we have completed in the past.

(d)is a deterministic network technique that allows for time/cost trade-offs.

(e)all of the above

13.90In CPM,

(a)an activity may start before its immediate predecessors have finished.

(b)no more than two activities may be performed simultaneously.

(c)the total cost of completing an activity in the crash time is higher than the normal cost.

(d)when we crash an activity, we complete the activity in the minimum possible time.

(e)none of the above

13.91Managers use the network analysis of PERT and CPM to help them

(a)identify the need for contingency plans by identifying critical activities.

(b)learn more about the actual times required to complete the activities.

(c)understand the relationship between the various activities.

(d)all of the above

(e)(a) & (c) only

13.92In contrast to CPM, PERT

(a)is a deterministic network model.

(b)requires all activities to be completed.

(c)assumes that activity costs are unknown.

(d)can identify activities which may, but do not necessarily, lie on the critical path.

(e)all of the above

13.93The expected time in PERT is

(a)greater than the most likely time.

(b)equal to the most likely time.

(c)less than the most likely time.

(d)could be any of the above.

(e)none of the above

13.94Given the following activity’s optimistic, most likely, and pessimistic time estimates of 3, 7, and 11 days, respectively, compute the expected time for this activity.

(a)5

(b)6

(d)12

(e)none of the above

13.95Given the following activity’s optimistic, most likely, and pessimistic time estimates of 3, 5, and 13 days, respectively, compute the expected time for this activity.