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Chapter 9 Project Scheduling: Networks, Duration Estimation, and Critical Path 9.1 True/False 1) Preceding activities are those that must occur before others can be done. Answer: TRUE Diff: 1 Section: 9.1 Project Scheduling Skill: Factual AACSB Tag: Reflective 2) A backward pass is performed when it is necessary to undo some work that has been performed in order to complete it properly. Answer: FALSE Diff: 1 Section: 9.2 Key Scheduling Terminology Skill: Factual AACSB Tag: Reflective 3) A merge activity has two or more immediate predecessors. Answer: TRUE Diff: 1 Section: 9.2 Key Scheduling Terminology Skill: Definition AACSB Tag: Reflective 4) Float is always measured in exactly the same way as slack. Answer: TRUE Diff: 2 Section: 9.2 Key Scheduling Terminology Skill: Factual AACSB Tag: Reflective 5) You must know the mean of an activity in order to determine its standard deviation. Answer: FALSE Diff: 2 Section: 9.4 Duration Estimation Skill: Factual AACSB Tag: Reflective
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Page 1: Chapter 9

Chapter 9 Project Scheduling: Networks, Duration Estimation, and Critical Path

9.1 True/False

1) Preceding activities are those that must occur before others can be done.Answer: TRUEDiff: 1Section: 9.1 Project SchedulingSkill: FactualAACSB Tag: Reflective

2) A backward pass is performed when it is necessary to undo some work that has been performed in order to complete it properly.Answer: FALSEDiff: 1Section: 9.2 Key Scheduling TerminologySkill: FactualAACSB Tag: Reflective

3) A merge activity has two or more immediate predecessors.Answer: TRUEDiff: 1Section: 9.2 Key Scheduling TerminologySkill: DefinitionAACSB Tag: Reflective

4) Float is always measured in exactly the same way as slack.Answer: TRUEDiff: 2Section: 9.2 Key Scheduling TerminologySkill: FactualAACSB Tag: Reflective

5) You must know the mean of an activity in order to determine its standard deviation.Answer: FALSEDiff: 2Section: 9.4 Duration EstimationSkill: FactualAACSB Tag: Reflective

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6) In assigning a value for the most pessimistic (b) duration, the project manager should estimate the duration of the activity to have a 99% likelihood that it will take b or less amount of time.Answer: TRUEDiff: 2Section: 9.4 Duration EstimationSkill: DefinitionAACSB Tag: Reflective7) The late start time should be calculated using a forward pass through the network.Answer: FALSEDiff: 2Section: 9.4 Duration EstimationSkill: FactualAACSB Tag: Reflective

8) Negative float exists when a project's critical path has been completed more quickly than anticipated.Answer: TRUEDiff: 2Section: 9.4 Duration EstimationSkill: FactualAACSB Tag: Reflective

9) Laddering is a technique that allows the project manager to redraw the network to more closely sequence project subtasks to make the overall network sequence more efficient.Answer: TRUEDiff: 2Section: 9.4 Duration EstimationSkill: FactualAACSB Tag: Reflective

10) Hammock activities break a task into greater levels of detail so that each task is represented as two or more subtasks that each have their own duration and precedence requirements.Answer: FALSEDiff: 2Section: 9.4 Duration EstimationSkill: FactualAACSB Tag: Reflective

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9.2 Fill in the Blank

1) __________ is the identification of the project objectives and the ordered activity necessary to complete the project.Answer: Project planningDiff: 1Section: 9.1 Project SchedulingSkill: DefinitionAACSB Tag: Reflective

2) The late finish times are determined by taking a(n) __________ through the network.Answer: backward passDiff: 1Section: 9.2 Key Scheduling TerminologySkill: FactualAACSB Tag: Analytic Skills

3) Activities that can be worked on simultaneously are __________ activities.Answer: concurrentDiff: 1Section: 9.3 Developing a NetworkSkill: DefinitionAACSB Tag: Reflective4) __________ activities have two or more immediate predecessors.Answer: MergeDiff: 1Section: 9.3 Developing a NetworkSkill: DefinitionAACSB Tag: Reflective

5) __________ activities have two or more immediate successors.Answer: BurstDiff: 1Section: 9.3 Developing a NetworkSkill: DefinitionAACSB Tag: Reflective

6) Because an activity's pessimistic estimate may represent a much greater deviation from the most likely time than its optimistic estimate, the __________ better represents the distribution of possible alternative durations.Answer: beta distributionDiff: 1Section: 9.4 Duration EstimationSkill: ConceptualAACSB Tag: Reflective

Page 4: Chapter 9

7) The longest route through the network is the __________.Answer: critical pathDiff: 1Section: 9.5 Constructing the Critical PathSkill: DefinitionAACSB Tag: Reflective

8) There is no slack on the project __________.Answer: critical pathDiff: 1Section: 9.5 Constructing the Critical PathSkill: FactualAACSB Tag: Reflective

9) Thanks to excessive dilly dallying, the subcontractor grossly exceeded the slack on his portion of the project, resulting in __________.Answer: negative floatDiff: 2Section: 9.5 Constructing the Critical PathSkill: ConceptualAACSB Tag: Reflective

10) __________ activities can be used as summaries for some subsets of the activities identified in the overall project network.Answer: HammockDiff: 2Section: 9.5 Constructing the Critical PathSkill: FactualAACSB Tag: Reflective9.3 Multiple Choice

1) The term ordered activity means:A) tasks must either precede or follow other tasks in project planning and management.B) tasks cannot be performed unless the project manager issues a specific command to perform the work.C) prior project planning removes the need for any rush so that tasks can be performed in a methodical fashion.D) tasks are not performed unless the customer issues a specific request to perform the work.Answer: ADiff: 1Section: 9.1 Project SchedulingSkill: DefinitionAACSB Tag: Reflective

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2) A sequence of activities defined by the project network logic is a(n):A) event.B) path.C) node.D) route.Answer: BDiff: 1Section: 9.2 Key Scheduling TerminologySkill: DefinitionAACSB Tag: Reflective

3) One of the defining points of a network, a junction point joined to some or all of the others by dependency lines, is called a(n):A) event.B) path.C) node.D) burst.Answer: CDiff: 1Section: 9.2 Key Scheduling TerminologySkill: DefinitionAACSB Tag: Reflective

4) These can be located by doing a backward pass through a network.A) critical pathsB) merge activitiesC) successorsD) burst activitiesAnswer: DDiff: 2Section: 9.2 Key Scheduling TerminologySkill: FactualAACSB Tag: Reflective5) An activity with two or more immediate predecessors is a(n):A) merge activity.B) burst activity.C) float activity.D) event.Answer: ADiff: 1Section: 9.2 Key Scheduling TerminologySkill: DefinitionAACSB Tag: Reflective

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6) The amount of time an activity may be delayed from its early start without delaying the finish of the project is the:A) delay.B) float.C) late start.D) late finish.Answer: BDiff: 2Section: 9.2 Key Scheduling TerminologySkill: FactualAACSB Tag: Reflective

7) The least amount of float is found:A) in a resource-limited schedule.B) after a burst activity.C) on the critical path.D) after a merge activity.Answer: CDiff: 1Section: 9.2 Key Scheduling TerminologySkill: DefinitionAACSB Tag: Reflective

8) Prior to creating a network, it is important to:A) identify all loops through activities.B) identify the party responsible for each activity.C) calculate the float for each activity.D) understand the activity precedence.Answer: DDiff: 2Section: 9.3 Developing a NetworkSkill: ConceptualAACSB Tag: Reflective9) Serial activities are those that:A) flow from one to the next in sequence.B) have sequential numbers.C) have the same numbers.D) should be performed simultaneously.Answer: ADiff: 1Section: 9.3 Developing a NetworkSkill: FactualAACSB Tag: Reflective

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10) Concurrent activities are:A) activities that must be done one after the other.B) activities that can be performed at the same time.C) activities that use labor from the same group of workers.D) activities that use resources from the same resource pool.Answer: BDiff: 1Section: 9.3 Developing a NetworkSkill: FactualAACSB Tag: Reflective

11) Which of these statements about this network is best?

A) Activities A and B are serial activities.B) Activities B and C are serial activities.C) Activities A and C are serial activities.D) Activity D is a merge activity.Answer: DDiff: 1Section: 9.3 Developing a NetworkSkill: ConceptualAACSB Tag: Reflective

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12) Network logic suggests that:

A) Activity D can start any time.B) Activity A must be complete before Activity B can be done.C) Activities A, B and C must be complete before Activity D can be done.D) Activity C must begin before Activity B begins.Answer: CDiff: 1Section: 9.3 Developing a NetworkSkill: ConceptualAACSB Tag: Reflective

13) What is the earliest that Activity D can begin if Activity A takes 3 days, Activity B takes 5 days, and Activity C takes 7 days?

A) day 15B) day 7C) day 5D) day 3Answer: BDiff: 1Section: 9.3 Developing a NetworkSkill: AnalyticalAACSB Tag: Analytic Skills

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14) Based on the activity network pictured, what is the best statement?

A) Before starting Activity C, Activity A, and Activity B must be completed.B) Before starting Activity D, Activity A, and Activity B need to be completed.C) Before starting Activity E, Activity A, and Activity B need to be completed.D) Before starting Activity C, Activity A, and Activity D must be completed.Answer: ADiff: 1Section: 9.3 Developing a NetworkSkill: AnalyticalAACSB Tag: Analytic Skills

15) Based on the activity network pictured, what is the best statement?

A) Activity C is a burst activity.B) Activity E has one predecessor, Activity B.C) Activity A and Activity C are merge activities.D) There are no serial activities in this network.Answer: BDiff: 1Section: 9.3 Developing a NetworkSkill: FactualAACSB Tag: Reflective

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16) The length of time expected to complete an activity assuming that its development proceeds normally is called the:A) optimistic duration.B) pessimistic duration.C) most likely duration.D) normal duration.Answer: CDiff: 1Section: 9.4 Duration EstimationSkill: DefinitionAACSB Tag: Reflective17) Ray's shipment of materials hit every red light and traffic jam on the way to the site. Upon arrival, half of the material was judged defective, necessitating a trip back to the supplier, and then the same arduous journey back to the site once the new materials were loaded. Traffic was a little better on the second round but the flat tire and subsequent repair caused as much if not more delay than the first trip. In the final analysis:A) the project activity of Material Delivery was pretty close to the optimistic estimate.B) the project activity of Material Delivery was pretty close to the most likely estimate.C) the project activity of Material Delivery had a much higher variance than anticipated.D) the project activity of Material Delivery was pretty close to the pessimistic estimate.Answer: DDiff: 1Section: 9.4 Duration EstimationSkill: FactualAACSB Tag: Reflective

18) The variance of an activity is given by:A) [1/6(b-a)]2.B) 1/6[b-a].C) [1/36(b-a)]2.D) 1/36[b-a].Answer: ADiff: 2Section: 9.4 Duration EstimationSkill: DefinitionAACSB Tag: Analytic Skills

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19) An activity has an optimistic time estimate of 15 days, a most likely estimate of 24 days, and a pessimistic estimate of 40 days. What is the expected duration of the activity?A) less than 27 days but greater than or equal to 26 daysB) less than 26 days but greater than or equal to 25 daysC) less than 25 days but greater than or equal to 24 daysD) less than 24 daysAnswer: BDiff: 2Section: 9.4 Duration EstimationSkill: AnalyticalAACSB Tag: Analytic Skills

20) An activity has an optimistic time estimate of 15 days, a most likely estimate of 24 days, and a pessimistic estimate of 40 days. What is the variance of the activity?A) 4.17B) 25.17C) 17.36D) 10.33Answer: CDiff: 2Section: 9.4 Duration EstimationSkill: AnalyticalAACSB Tag: Analytic Skills21) An activity has an optimistic time estimate of 7 days, a most likely estimate of 12 days, and a pessimistic estimate of 20 days. What is the expected duration of the activity?A) 13 daysB) 13.5 daysC) 12 daysD) 12.5 daysAnswer: DDiff: 2Section: 9.4 Duration EstimationSkill: AnalyticalAACSB Tag: Analytic Skills

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22) An activity has an optimistic time estimate of 7 days, a most likely estimate of 12 days, and a pessimistic estimate of 20 days. What is the expected standard deviation of the activity?A) between 2 and 3 daysB) between 3 and 4 daysC) between 4 and 5 daysD) between 5 and 6 daysAnswer: DDiff: 2Section: 9.4 Duration EstimationSkill: AnalyticalAACSB Tag: Analytic Skills

23) An activity has a pessimistic time that is three times as long as its most likely time and five times as long as its optimistic time. If the activity variance is 10, what is the expected time?A) about 10 daysB) about 14 daysC) about 19 daysD) about 23 daysAnswer: ADiff: 2Section: 9.4 Duration EstimationSkill: AnalyticalAACSB Tag: Analytic Skills

24) Activity Z has estimates a=5, b=10, m=7; activity X has estimates a=4, b=11, m=6; and activity Y has estimates a=3, b=12, m=8. Which of the following statements is best?A) Activity X is longer than Activity Y.B) Activity X has a higher standard deviation than Activity ZC) Activity Z is shorter than Activity Y.D) Activity Y has a smaller variance than Activity Z.Answer: BDiff: 2Section: 9.4 Duration EstimationSkill: AnalyticalAACSB Tag: Analytic Skills

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25) What is the early start time for Activity D given the activity times and precedence requirements shown in the table?

ActivityTimePredecessorA5--B8AC4AD5B, CA) 5B) 9C) 13D) 18Answer: CDiff: 2Section: 9.5 Constructing the Critical PathSkill: AnalyticalAACSB Tag: Analytic Skills

26) What is the late start time for Activity B given the activity times and precedence requirements shown in the table?

ActivityTimePredecessorA5--B8AC4AD5B, CA) 18B) 9C) 13D) 5Answer: DDiff: 2Section: 9.5 Constructing the Critical PathSkill: AnalyticalAACSB Tag: Analytic Skills

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27) What is the late start time for Activity E given the activity times and precedence requirements shown in the table?

ActivityTimePredecessorA4--B7--C8AD2AE4BF5C, DG9E, FH7GA) 12B) 13C) 14D) 15Answer: BDiff: 3Section: 9.5 Constructing the Critical PathSkill: AnalyticalAACSB Tag: Analytic Skills

28) What is the late finish time for Activity D given the activity times and precedence requirements shown in the table?

ActivityTimePredecessorA4--B7--C8AD2AE4BF5C, DG9E, FH7GA) 14B) 13C) 12D) 11Answer: CDiff: 3Section: 9.5 Constructing the Critical PathSkill: AnalyticalAACSB Tag: Analytic Skills

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29) What is the early start time for Activity G given the activity times and precedence requirements shown in the table? ActivityTimePredecessorA4--B7--C8AD2AE4BF5C, DG9E, FH7GA) 14B) 15C) 16D) 17Answer: DDiff: 3Section: 9.5 Constructing the Critical PathSkill: AnalyticalAACSB Tag: Analytic Skills

30) What is the early finish time for Activity F given the activity times and precedence requirements shown in the table? ActivityTimePredecessorA4--B7--C8AD2AE4BF5C, DG9E, FH7GA) 17B) 12C) 13D) 26Answer: ADiff: 3Section: 9.5 Constructing the Critical PathSkill: AnalyticalAACSB Tag: Analytic Skills

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31) What is the slack time for Activity B given the activity times and precedence requirements shown in the table? ActivityTimePredecessorA4--B7--C8AD2AE4BF5C, DG9E, FH7GA) 7B) 6C) 5D) 4Answer: BDiff: 3Section: 9.5 Constructing the Critical PathSkill: AnalyticalAACSB Tag: Analytic Skills

32) What is the slack time for Activity C given the activity times and precedence requirements shown in the table? ActivityTimePredecessorA4--B7--C8AD2AE4BF5C, DG9E, FH7GA) 2B) 1C) 0D) 3Answer: CDiff: 3Section: 9.5 Constructing the Critical PathSkill: AnalyticalAACSB Tag: Analytic Skills

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33) What is the float start time for Activity C given the activity times and precedence requirements shown in the table? ActivityTimePredecessorA5--B8AC4AD5B, CA) 1B) 2C) 3D) 4Answer: DDiff: 2Section: 9.5 Constructing the Critical PathSkill: AnalyticalAACSB Tag: Analytic Skills

34) Use the information in the table to determine the late start time for Activity E. TaskPredecessorDurationEarly StartEarly FinishLate StartLate FinishA--8BA14CA238DC, B62326EC32FD, E3238A) day 23B) day 26C) day 32D) day 17Answer: ADiff: 3Section: 9.5 Constructing the Critical PathSkill: AnalyticalAACSB Tag: Analytic Skills

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35) Use the information in the table to determine the early start time for Activity B. TaskPredecessorDurationEarly StartEarly FinishLate StartLate FinishA--8BA14CA238DC, B62326EC32FD, E3238A) day 10B) day 8C) day 9D) day 11Answer: BDiff: 1Section: 9.5 Constructing the Critical PathSkill: AnalyticalAACSB Tag: Analytic Skills

36) Use the information in the table to determine the early finish time for Activity D. TaskPredecessorDurationEarly StartEarly FinishLate StartLate FinishA--8BA14CA238DC, B62326EC32FD, E3238A) day 23B) day 26C) day 29D) day 32Answer: CDiff: 3Section: 9.5 Constructing the Critical PathSkill: AnalyticalAACSB Tag: Analytic Skills

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37) Use the information in the table to determine the late finish time for Activity B. TaskPredecessorDurationEarly StartEarly FinishLate StartLate FinishA--8BA14CA238DC, B62326EC32FD, E3238A) day 17B) day 26C) day 20D) day 23Answer: DDiff: 3Section: 9.5 Constructing the Critical PathSkill: AnalyticalAACSB Tag: Analytic Skills

38) Use the information in the table to determine the slack time for Activity B. TaskPredecessorDurationEarly StartEarly FinishLate StartLate FinishA--8BA14CA238DC, B62326EC32FD, E3238A) 6 daysB) 4 daysC) 2 daysD) 0 daysAnswer: ADiff: 3Section: 9.5 Constructing the Critical PathSkill: AnalyticalAACSB Tag: Analytic Skills

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39) What is the slack time for activity E? TaskPredecessorDurationEarly StartEarly FinishLate StartLate FinishA--8BA14CA238DC, B62326EC32FD, E3238A) 1 dayB) 0 daysC) 2 daysD) 4 daysAnswer: BDiff: 3Section: 9.5 Constructing the Critical PathSkill: AnalyticalAACSB Tag: Analytic Skills

40) Use the network diagram and activity lengths in the nodes to determine the early start time for activity D.

A) 8B) 13C) 14D) 21Answer: CDiff: 1Section: 9.5 Constructing the Critical PathSkill: AnalyticalAACSB Tag: Analytic Skills

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41) Use the network diagram and activity lengths in the nodes to determine the late start time for activity F.

A) 21B) 24C) 26D) 23Answer: DDiff: 2Section: 9.5 Constructing the Critical PathSkill: AnalyticalAACSB Tag: Analytic Skills

42) Use the network diagram and activity lengths in the nodes to determine the early finish time for activity G.

A) 26B) 25C) 24D) 23Answer: ADiff: 1Section: 9.5 Constructing the Critical PathSkill: AnalyticalAACSB Tag: Analytic Skills

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43) Use the network diagram and activity lengths in the nodes to determine the late finish time for activity C.

A) 12B) 13C) 14D) 15Answer: CDiff: 2Section: 9.5 Constructing the Critical PathSkill: AnalyticalAACSB Tag: Analytic Skills

44) Use the network diagram and activity lengths in the nodes to determine the slack time for activity D.

A) 3B) 2C) 1D) 0Answer: DDiff: 1Section: 9.5 Constructing the Critical PathSkill: AnalyticalAACSB Tag: Analytic Skills

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45) Use the network diagram and activity lengths in the nodes to determine the early start time for activity D.

A) 8B) 13C) 14D) 21Answer: CDiff: 1Section: 9.5 Constructing the Critical PathSkill: AnalyticalAACSB Tag: Analytic Skills

46) There's an old saying, "The job is not finished until the paperwork is done." From an activity network standpoint, this does not necessarily mean that the paperwork can't begin until the last non-paperwork activity is completed. It might be possible to work on some paperwork as early activities are completed. In order to depict this in an activity network:A) hammock activities could be drawn.B) subroutines could be added.C) shortcuts can be added to the network.D) laddering could be used to redraw the network.Answer: DDiff: 2Section: 9.5 Constructing the Critical PathSkill: ConceptualAACSB Tag: Reflective

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47) Project Test Bank is composed of activities we will refer to as A, B, C, and D for convenience (and lack of creativity). Durations and precedence requirements are shown in the table. Each of these activities can be conveniently laddered into two sub-activities of equal duration. The first half of each activity serves as the predecessor to its second half and the first half of the original following activity. What is the expected completion time of the laddered project? ActivityLengthPredecessorA10--B18AC14AD20B, CA) 34B) 38C) 42D) 48Answer: ADiff: 3Section: 9.5 Constructing the Critical PathSkill: AnalyticalAACSB Tag: Analytic Skills

48) Project Test Bank is composed of activities we will refer to as A, B, C, and D for convenience (and lack of creativity). Durations and precedence requirements are shown in the table. Each of these activities can be conveniently laddered into two sub-activities of equal duration. The first half of each activity serves as the predecessor to its second half and the first half of the original following activity. What is the expected completion time of the laddered project? ActivityLengthPredecessorA10--B18AC14AD20B, CA) 34B) 38C) 42D) 48Answer: BDiff: 3Section: 9.5 Constructing the Critical PathSkill: AnalyticalAACSB Tag: Analytic Skills

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49) Project Test Bank is composed of activities we will refer to as A, B, C, and D for convenience (and lack of creativity). Durations and precedence requirements are shown in the table. Each of these activities can be conveniently laddered into two sub-activities of equal duration, so activity C in the original project becomes two activities, C1 and C2, each of which last 7 days. The first half of each activity serves as the predecessor to its second half and the first half of the original following activity. What is difference in the late start time for activity C in the original project and activity C1 in the laddered project? ActivityLengthPredecessorA10--B18AC14AD20B, CA) 3B) 5C) 7D) 9Answer: CDiff: 3Section: 9.5 Constructing the Critical PathSkill: AnalyticalAACSB Tag: Analytic Skills

50) The overall effect of laddering activities is to:A) streamline the linkage and sequencing between activities and keep project resources fully employed.B) summarize some subsets of the activities identified in the overall project network.C) allow the project team to disaggregate the overall project network into logical summaries.D) allow the project manager to more fully deploy resources and complete the project with zero slack.Answer: ADiff: 2Section: 9.5 Constructing the Critical PathSkill: ConceptualAACSB Tag: Reflective

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51) Summaries for some subsets of the activities identified in the overall project network are called:A) ladder activities.B) hammock activities.C) negative float activities.D) compressed activities.Answer: BDiff: 2Section: 9.5 Constructing the Critical PathSkill: DefinitionAACSB Tag: Reflective52) Hammock activities allow:A) project managers to streamline the linkage and sequencing between activities.B) project workers to effectively skip nonessential activities without compromising project quality.C) the project team to better disaggregate the overall project network into subsets.D) the project manager to identify float more quickly and leverage it more successfully for the overall success of the project.Answer: CDiff: 2Section: 9.5 Constructing the Critical PathSkill: FactualAACSB Tag: Reflective

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53) Activities C, D, and E in the project represented by the network are to be hammocked. What is the activity length of the hammock activity?

A) 20B) 16C) 13D) 11Answer: ADiff: 1Section: 9.5 Constructing the Critical PathSkill: AnalyticalAACSB Tag: Analytic Skills

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54) Activities C, D, and E in the project represented by the network are to be hammocked. What are the early start and late finish times of the hammock activity?

A) 6, 20B) 6, 26C) 9, 20D) 9, 26Answer: BDiff: 2Section: 9.5 Constructing the Critical PathSkill: AnalyticalAACSB Tag: Analytic Skills

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55) Activities C, D, and E in the project represented by the network are to be hammocked. What are the late start and early finish times of the hammock activity?

A) 6, 24B) 6, 26C) 8, 24D) 8, 26Answer: CDiff: 2Section: 9.5 Constructing the Critical PathSkill: AnalyticalAACSB Tag: Analytic Skills

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56) A project has the precedence requirements and activity durations shown in the table. After he draws the network, the project manager decides that activities B, C, and D can be represented by a hammock activity. What are the early start and late finish times associated with this hammock activity? TimePredecessorA7B8AC13BD8CE7AF6EG6AH11GI12HJ14D, F, IA) 11, 30B) 7, 24C) 11, 24D) 7, 36Answer: DDiff: 2Section: 9.5 Constructing the Critical PathSkill: AnalyticalAACSB Tag: Analytic Skills

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57) A project has the precedence requirements and activity durations shown in the table. After he draws the network, the project manager decides that activities H and I can be represented by a hammock activity. What are the early start and late finish times associated with this hammock activity? TimePredecessorA7B8AC13BD8CE7AF6EG6AH11GI12HJ14D, F, IA) 13, 36B) 13, 24C) 24, 36D) 7, 36Answer: ADiff: 2Section: 9.5 Constructing the Critical PathSkill: AnalyticalAACSB Tag: Analytic Skills

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58) A project has the precedence requirements and activity durations shown in the table. After he draws the network, the project manager decides to represent a few activities by as hammock activity. Which is a legitimate hammock activity for this project?

TimePredecessorA7B8AC13AD8AE7BF6CG6DH11EI12GJ14H, F, IA) combine activities A, B, CB) combine activities B, E, HC) combine activities E, FD) combine activities G, H, IAnswer: BDiff: 1Section: 9.5 Constructing the Critical PathSkill: AnalyticalAACSB Tag: Analytic Skills

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59) A project has the precedence requirements and activity durations shown in the table. After he draws the network, the project manager decides that activities E and F can be represented by a hammock activity. What are the duration and the early start time associated with this hammock activity?

TimePredecessorA7B8AC13BD8CE7AF6EG6AH11GI12HJ14D, F, IA) 13, 36B) 7, 0C) 13, 7D) 7, 14Answer: CDiff: 1Section: 9.5 Constructing the Critical PathSkill: AnalyticalAACSB Tag: Analytic Skills

60) One approach to reducing project length would be to:A) convert parallel paths to be serial.B) convert merge activities to burst activities.C) use hammock activities in place of multiple activities.D) eliminate tasks on the critical path.Answer: DDiff: 2Section: 9.5 Constructing the Critical PathSkill: ConceptualAACSB Tag: Reflective

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61) A project's duration can be reduced by:A) shortening the duration of critical path tasks.B) adding tasks to the critical path.C) adding shorter routes around the critical path.D) completing the backward pass first.Answer: ADiff: 1Section: 9.5 Constructing the Critical PathSkill: ConceptualAACSB Tag: Reflective62) The best candidate activities for shortening the overall project are:A) the shortest tasks.B) the longest tasks.C) the merge tasks.D) the burst tasks.Answer: BDiff: 1Section: 9.5 Constructing the Critical PathSkill: ConceptualAACSB Tag: Reflective

63) Which technique would accelerate the completion of a project?A) hammockingB) burstingC) ladderingD) passingAnswer: CDiff: 1Section: 9.5 Constructing the Critical PathSkill: FactualAACSB Tag: Reflective

64) In order to reduce the length of a project, it would be wise to shorten:A) the project activity that costs the least to speed up.B) the project activity that can be speeded up by the greatest amount.C) the critical path activity that can be speeded up by the greatest amount.D) the critical path activity that costs the least to speed up.Answer: DDiff: 1Section: 9.5 Constructing the Critical PathSkill: ConceptualAACSB Tag: Reflective

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65) In general, the better candidates for shortening are:A) early tasks opposed to later tasks.B) later tasks opposed to early tasks.C) merge tasks opposed to burst tasks.D) burst tasks opposed to merge tasks.Answer: ADiff: 1Section: 9.5 Constructing the Critical PathSkill: ConceptualAACSB Tag: Reflective9.4 Essay

1) What does a network diagram illustrate and why are they important in project management?Answer: A network diagram is a schematic display of the project's work packages and the logical relationships and interdependencies among them. For this reason, the network diagram facilitates communication flows and helps with the master scheduling of organizational resources because it shows times when personnel must be fully committed to project activities. The network diagram also identifies the critical activities and distinguishes them from the less critical and when each must start and end in order to keep the project on schedule and complete it on time.Diff: 2Section: 9.1 Project SchedulingSkill: ConceptualAACSB Tag: Reflective

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2) Draw a network of any size that has at least one of each of the following features: merge activity, burst activity, hammock activity, ladder activity, critical path, serial activities, concurrent activities, critical path, and float. Mark these features on your network.Answer: Answers will vary, but here's an example. Activity C is a merge because it has two predecessors and a burst activity because it has two successors. Activities A and B are concurrent activities and activities D and F are serial activities. Activities E and G have been laddered and activities H and I are represented by a hammock activity. The critical path consists of activities ACDFHIJ. Activities B, E, and G have float.

Diff: 2Section: 9.1 Project SchedulingSkill: ConceptualAACSB Tag: Reflective

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3) Construct a network using the information in the table and identify the critical path.

ActivityTimePredecessorA4B6AC9AD11BE16B, CF4DG8E, FH7GAnswer: The network appears below; critical path is ACEGH. Early and late start and finish times are in the table below the network.

TaskEarly StartEarly FinishLate StartLate FinishA0404B410713C413413D10211425E13291329F21252529G29372937H37443744Diff: 2Section: 9.5 Constructing the Critical PathSkill: AnalyticalAACSB Tag: Analytic Skills

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4) Compute early and late start and finish times for the network shown.

Answer: Early and late start and finish times are given in the table.

TaskEarly StartEarly FinishLate StartLate FinishA0606B6111621C18272130D6101418E18301830F618618G30383038Diff: 2Section: 9.5 Constructing the Critical PathSkill: AnalyticalAACSB Tag: Analytic Skills

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5) Use the information in the table to sketch the network and compute early and late start times. ActivityTimePredecessorA8B4AC5B, FD12AE8DF4DG9E, FH12GI6C, GJ5IK9HL12J, KAnswer: The early and late start times are shown in the table and the network is below:

TaskEarly StartEarly FinishLate StartLate FinishA0808B8123842C24294247D820820E20282028F20242428G28372837H37493749I37434753J43485358K49584958L58705870

Diff: 2Section: 9.5 Constructing the Critical PathSkill: AnalyticalAACSB Tag: Analytic Skills

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6) Phoebe B. Beebee is constructing a canal for the annual canoe races and has identified eleven activities that are required to complete this important project. She calculated early and late start times and early and late finish times but spilled coffee all over her printout. Use the remaining information to reconstruct the table for Phoebe B. Beebee and her new canoe canal.

ActivityPredecessorLengthEarly StartLate StartEarly FinishLate FinishA--12BA20CADB, E42EC2842FE4250GD5353HG70IG72JF4KH, I, J8191Answer: The completed table appears below:

TaskPredecessorLengthEarly StartLate StartEarly FinishLate FinishA--12001212BA2012223242CA1612122828DB, E1142425353EC1428284242FE842695077GD1753537070HG1170708181IG970727981JF450775481KH, I, J1081819191Diff: 3Section: 9.5 Constructing the Critical PathSkill: AnalyticalAACSB Tag: Analytic Skills

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7) What are three methods of duration estimation for project activities and what are the advantages and disadvantages of each method?Answer: The text presents three alternative ways to estimate times, including past experience, expert opinion, and mathematical derivation. Past experience is easily leveraged but it assumes that the circumstances are the same and that what worked in the past will work tomorrow. Expert opinion calls upon past project managers or subject matter experts to get accurate information on activity estimates. Experts should have knowledge about how to perform an activity and how long it should take, but if they are not used to perform the work their estimates may be too low. Mathematical derivation offers an objective alternative to activity estimation by calling for optimistic, most likely, and pessimistic estimates of each activity. The gain in objectivity may be offset by the pain of developing three time estimates for each activity instead of just one.Diff: 2Section: 9.4 Duration EstimationSkill: ConceptualAACSB Tag: Reflective8) Use the values in the table to calculate activity durations and variances for the project. Which path is critical? How closely should the other path be watched and why? ActivityPredecessorOptimisticLikelyPessimisticA--4610BA258CA679DB3920EC7911FD,E71119Answer: The estimated activity lengths and variances appear in the table below. The critical path is ACEF at 34.17 days and path ABDF has duration of 32.83 days. The path variances are ACEF=5.69 and ABDF=14.02, resulting in standard deviations of 2.39 and 3.75 days, respectively. The higher variability associated with the non-critical path is cause for concern; it will take a movement of only one standard deviation above the mean for the non-critical path to become critical.Diff: 3Section: 9.4 Duration EstimationSkill: AnalyticalAACSB Tag: Analytic Skills

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9) What is the underlying theory to the three time estimates approach? What data distribution should be applied in this case and what confidence should a project manager place in the calculations associated with this technique?Answer: Probability suggests that the amount of time that an activity is likely to take is rarely deterministic; rather it is stochastic and found as the result of sampling a range of likelihoods of the event occurring. These likelihoods range from zero to one. In order to derive a reasonable estimate for the activity's duration, we identify the activity's most likely, pessimistic, and optimistic durations. From these time estimates we can use a symmetrical or asymmetrical probability distribution to develop a mean and standard deviation for each activity. A normal distribution might be used if the optimistic and pessimistic estimates are symmetrical to the mean and a beta distribution can be employed if the estimates are asymmetrical. The goal is to achieve a high level of confidence for the probability estimates; the higher the better in order to achieve a better estimate for the project duration.Diff: 1Section: 9.4 Duration EstimationSkill: ConceptualAACSB Tag: Reflective

10) What is laddering and what advantages can be gained from its use in project management?Answer: Laddering is a technique that allows us to redraw the activity network to more closely sequence the project subtasks to make the overall network sequence more efficient. Complicated activities are broken down into smaller activities by virtue of identifying milestones within them. If a successor activity can begin after the attainment of one of these milestones, then project resources can be more fully employed, project duration can be reduced and the linkage and sequencing between activities can be streamlined.Diff: 1Section: 9.5 Constructing the Critical PathSkill: FactualAACSB Tag: Reflective

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11) Consider a project composed activities X and Y having equal length and performed in that order. Both activities can be laddered such that the first half of each activity is the predecessor for its own second half, so X1 precedes X2 and Y1 precedes Y2. The first half of X1 is also the predecessor for Y1. If the laddering procedure were performed again activities X and Y would be divided in four parts each, with precedence working as it did in the first split. Derive an expression for the minimum length of the project as laddering increases.Answer: The original length of the project is X+Y. When laddering is performed the first time, the project length becomes X1+Y1+Y2; this is because X2 can be performed concurrently with Y1. If the activities are divided again, the project length will be X1+Y1+Y2+Y3+Y4; because X2 can be performed concurrently with Y1, X3 can be performed concurrently with Y2, and X4 can be performed concurrently with Y3.

In general, the project can be viewed as the length of Y plus the waiting time while completing the length of sub-activity X1. As the number of iterations of laddering these activities becomes large, the length of sub-activity X1 becomes small, reducing project length to the length of activity Y. Expressed mathematically where P is the project length:

Diff: 3Section: 9.5 Constructing the Critical PathSkill: AnalyticalAACSB Tag: Analytic Skills

12) What are hammock activities and when should they be used?Answer: Hammock activities can be used as summaries for some subsets of the activities identified in the overall project network. The hammock is named so because it hangs below the network path for tasks it is summarizing and serves as an aggregation for the activities it rolls up. Hammocks allow the project team to better disaggregate the overall project network into logical summaries. The process is helpful when the project network is extremely complex or consists of a large number of individual activities. It is also useful when the project budget if actually shared among a number of cost centers or departments. Hammocking the activities that are assignable to each cost center makes the job of cost accounting for the project easier.Diff: 1Section: 9.5 Constructing the Critical PathSkill: FactualAACSB Tag: Reflective

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13) Discuss any five approaches to reducing the critical path. Which is the most effective and which is the most difficult to achieve? Why?Answer: The text presents eight ways to reduce the critical path; answers will vary as to the most effective and most difficult to achieve depending on circumstances and students' intellectual capital. The alternatives presented are:Eliminate tasks on the critical path — tasks can be dropped or moved to non-critical paths, thereby shortening the critical path.Re-plan serial paths to be in parallel — if serial activities are converted to concurrent activities, project length can be reduced.Overlap sequential tasks — laddering is a good method for overlapping sequential activities.Shorten the duration on critical path tasks — if these tasks were improp�e�r�l�y� �e�s�t�i�m�a�t�e�d�,� �t�h�e�n� �t�h�e� �p�r�o�j�e�c�t� �l�e�n�g�t�h� �c�a�n� �b�e� �r�e�d�u�c�e�d�.��S�h�o�r�t�e�n� �e�a�r�l�y� �t�a�s�k�s� �à �t�h�e� �l�o�g�i�c� �h�e�r�e� �i�s� �t�h�a�t� �t�h�e�s�e� �t�a�s�k�s� �a�r�e� �m�o�r�e� �c�e�r�t�a�i�n�,� �b�e�i�n�g� �i�n� �t�h�e� �n�e�a�r� �f�u�t�u�r�e� �a�n�d� �s�u�c�h� �c�e�r�t�a�i�n�t�y� �c�a�n� �b�e� �t�a�k�e�n� �a�d�v�a�n�t�a�g�e� �o�f� �b�y� �t�i�m�e� �r�e�d�u�c�t�i�o�n�.��S�h�o�r�t�e�n� �l�o�n�g�e�s�t� �t�a�s�k�s� � �t�h�e� �l�o�n�g�e�s�t� tasks may have the same percentage padding and, as a result, the greatest amount of tie that can be cut.Shorten easiest tasks — duration estimates for the easiest tasks can be deflated without an adverse impact on the project team's work.Shorten tasks that cost the least to speed up — crashing critical path activities by throwing money at them should be performed with a budget and conscience.Diff: 2Section: 9.5 Constructing the Critical PathSkill: ConceptualAACSB Tag: Reflective