SCM 146 Chapter 3
Identify, in order, the six steps basic to both PERT and CPM.
1. Define the project and prepare the WBS. 2. Develop the relationships among the activities. 3. Draw the network connecting all of the activities. 4. Assign the time and/or cost estimates to each activity. 5. Compute the critical path-the longest time path through the network. 6. Use the network to help plan, schedule, monitor, and control the project.
A code of ethics especially for project managers: A) has been established by the Project Management Institute. B) has been formulated by the Federal government. C) has been formulated by the World Trade Organization. D) is inappropriate, since everyone should use the same guidance on ethical issues. E) does not exist at this time.
A
A combination of effective Gantt chart use and other tactics allowed Delta to cut the average time for a plane layover by what % of the original 60 minute duration? A) 33%, to 40 minutes B) 50%, to 30 minutes C) 20%, to 48 minutes D) 25%, to 45 minutes E) 40%, to 36 minutes
A
A contractor's project being analyzed by PERT has an estimated time for the critical path of 120 days. The sum of all activity variances is 81; the sum of variances along the critical path is 64. What is the probability that the project will take 130 or more days to complete? A) 0.1057 B) 0.1335 C) 0.8512 D) 0.8943 E) 1.29
A
A project manager is interested in crashing a project with variable activity times. Which of the following tools should he/she employ?
A
A project organization: A) is effective for companies with multiple large projects. B) is appropriate only in construction firms. C) often fails when the project cuts across organizational lines. D) is most helpful for ongoing projects with no termination date. E) is most helpful when the work contains simple and unrelated tasks.
A
An activity on a PERT network has these time estimates: optimistic = 2, most likely = 3, and pessimistic = 8. What is its expected activity time and variance? A) 3.67; 1 B) 3.67; 6 C) 4.33; 1 D) 4.33; 6 E) none of the above
A
If an activity whose normal duration is 13 days can be shortened to 10 days for an added cost of $1,500, what is the crash cost per period? A) $500 B) $1,500 C) $750 D) $13,000 E) $15,000
A
If an activity whose normal duration is 15 days can be shortened to 10 days for an added cost of $2,000, what is the crash cost per period? A) $400 B) $2,000 C) $10,000 D) $20,000 E) $30,000
A
The phases of project management are: A) planning, scheduling, and controlling. B) planning, programming, and budgeting. C) planning, organizing, staffing, leading, and controlling. D) different for manufacturing projects than for service projects. E) GANTT, CPM, and PERT.
A
What is a project organization?
A project organization is an organization formed to ensure that programs (projects) receive the proper management and attention.
A local project being analyzed by PERT has 42 activities, 13 of which are on the critical path. If the estimated time along the critical path is 105 days with a project variance of 25, what is the probability that the project will be completed in 95 days or less? A) -0.4 B) 0.0228 C) 0.3444 D) 0.9772 E) 4.2
B
A project being analyzed by PERT has 38 activities, 16 of which are on the critical path. If the estimated time along the critical path is 90 days with a project variance of 25, what is the probability that the project will be completed in 88 days or less? A) 0.0228 B) 0.3446 C) 0.6554 D) 0.9772 E) 18
B
A project organization that becomes permanent is often referred to as a: A) fixed project organization. B) matrix organization. C) normal organization. D) standard organization. E) permanent project organization.
B
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. Which of the following statements is true? A) There are two paths in this network. B) There are four paths in this network. C) There are five paths in this network. D) There are 25 paths in this network. E) There are six paths in this network.
B
An activity on a PERT network has these time estimates: optimistic = 1, most likely = 2, and pessimistic = 5. What is its expected activity time? A) 2.00 B) 2.33 C) 2.67 D) 4.67 E) 14.00
B
An activity on a PERT network has these time estimates: optimistic = 2, most likely = 5, and pessimistic = 10. What is its expected activity time? A) 5.00 B) 5.33 C) 5.67 D) 10.67 E) 32.00
B
In a PERT network, non-critical activities that have little slack need to be monitored closely: A) because PERT treats all activities as equally important. B) because near-critical paths could become critical paths with small delays in these activities. C) because slack is undesirable and needs to be eliminated. D) because they are causing the entire project to be delayed. E) because they have a high risk of not being completed.
B
The expected activity time in PERT analysis is calculated as: A) the simple average of the optimistic, pessimistic, and most likely times. B) the weighted average of a, m, and b, with m weighted 4 times as heavily as a and b. C) the sum of the optimistic, pessimistic, and most likely times. D) the sum of the optimistic, pessimistic, and most likely times, divided by six. E) the sum of the activity variances, divided by six.
B
Which of the following statements about Bechtel is true? A) Even though Bechtel is over 100 years old, the Kuwaiti oil fields was its first "project." B) Bechtel is the world's premier manager of massive construction and engineering projects. C) Bechtel's competitive advantage is supply chain management. D) While its projects are worldwide, its network of suppliers is largely in the United States E) All of the above are true.
B
Which of the following statements regarding time-cost tradeoffs in CPM networks is false? A) Crashing shortens project duration by assigning more resources to critical tasks. B) Crashing sometimes has the reverse result of lengthening the project duration. C) Crashing must consider the impact of crashing an activity on all paths in the network. D) Activities not on the critical path can become critical after crashing takes place. E) A negative crash cost per period would imply that either crashing is cheaper than not crashing or that the crash time was slower than the normal time.
B
A project being analyzed by PERT has 60 activities, 13 of which are on the critical path. If the estimated time along the critical path is 214 days with a project variance of 100, what is the probability that the project will take 224 days or more to complete? A) near zero B) 0.0126 C) 0.1587 D) 0.8413 E) 2.14
C
Activity R on a CPM network has predecessors M and N, and has successor S. R has duration 5. N's late finish is 18, while M's is 20. S's late start is 14. Which of the following is definitely true? A) R is critical and has zero slack. B) R has no slack but is not critical. C) The set of times cannot all be possible. D) N is a critical activity. E) S is a critical activity.
C
The beta distribution is used in project management to: A) determine which activity should be crashed. B) calculate the probability that a project will be completed within its budget. C) calculate expected activity times. D) calculate slack for activities on the critical path. E) none of the above
C
Which of the following statements regarding Gantt charts is true? A) Gantt charts give a timeline and precedence relationships for each activity of a project. B) Gantt charts use the four standard spines of Methods, Materials, Manpower, and Machinery. C) Gantt charts are visual devices that show the duration of activities in a project. D) Gantt charts are expensive. E) All of the above are true.
C
Which of the following statements regarding PERT times is true? A) The expected time is an estimate of the time an activity will require if everything goes as planned. B) The optimistic time estimate is an estimate of the maximum time an activity will require. C) The expected time estimate is calculated as t = (a + 4m + b)/6. D) The pessimistic time estimate is an estimate of the minimum time an activity will require. E) The most likely time estimate is an estimate of the maximum time an activity will require.
C
A PERT project has 45 activities, 19 of which are on the critical path. The estimated time for the critical path is 120 days. The sum of all activity variances is 64, while the sum of variances along the critical path is 36. What is the probability that the project can be completed between days 108 and 120? A) -2.00 B) 0.0227 C) 0.1058 D) 0.4773 E) 0.9773
D
A network has been crashed to the point where all activities are critical. Additional crashing: A) is unnecessary. B) is impossible. C) is prohibitively expensive. D) may require crashing multiple tasks simultaneously. E) can be done, but all critical tasks must be reduced in duration.
D
Activity D on a CPM network has predecessors B and C, and has successor F. D has duration 6. B's earliest finish is 18, while C's is 20. F's late start is 26. Which of the following is definitely true? A) B is a critical activity. B) C is completed before B. C) D has no slack but is not critical. D) D is critical, and has zero slack. E) F is critical, and has zero slack.
D
WBS stands for which of the following project management tools? A) work break schedule B) work breakdown status C) work breakdown schedule D) work breakdown structure E) work break status
D
Which of the following statements concerning CPM activities is false? A) The early finish of an activity is the early start of that activity plus its duration. B) The late finish is the earliest of the late start times of all successor activities. C) The late start of an activity is its late finish less its duration. D) The late finish of an activity is the earliest late start of all preceding activities. E) The early start of an activity is the latest early finish of all preceding activities.
D
Which of the following statements regarding CPM is true? A) The critical path is the shortest of all paths through the network. B) The critical path is that set of activities that has positive slack. C) Some networks have no critical path. D) All activities on the critical path have their LS equal to the maximum EF of all immediate predecessors. E) All activities on the critical path have their ES equal to their LF.
D
Which of the following statements regarding CPM networks is true? A) There can be multiple critical paths on the same project, all with different durations. B) The early finish of an activity is the latest early start of all preceding activities. C) The late start of an activity is its late finish plus its duration. D) If a specific project has multiple critical paths, all of them will have the same duration. E) None of the above are true.
D
Which of the following statements regarding PERT analysis is true? A) Each activity has two estimates of its duration. B) Project variance is the sum of all activity variances. C) Project standard deviation is the sum of all critical activity standard deviations. D) Only critical activities contribute to the project variance. E) The most likely time is equivalent to the expected activity time.
D
Which of the following statements regarding critical paths is true? A) The shortest of all paths through the network is the critical path. B) Some activities on the critical path may have slack. C) Every network has only one critical path. D) On a specific project, there can be multiple critical paths, all with exactly the same duration. E) The duration of the critical path is the average duration of all paths in the project network.
D
Which of these statements regarding time-cost tradeoffs in CPM networks is true? A) Crashing is not possible unless there are multiple critical paths. B) Crashing a project often reduces the length of long-duration, but noncritical, activities. C) Activities not on the critical path can never be on the critical path, even after crashing. D) Crashing shortens the project duration by assigning more resources to one or more of the critical tasks. E) The crash time always exceeds the normal time.
D
Analysis of a PERT problem shows the estimated time for the critical path to be 108 days with a variance of 64. There is a .90 probability that the project will be completed before approximately day: A) 98. B) 108. C) 109. D) 115. E) 118.
E
Ethical issues that may arise in projects large and small include: A) gifts from contractors. B) exaggerated expense reports. C) compromised quality standards to meet bonuses or avoid penalties related to schedules. D) pressure to mask delays with false status reports. E) all of the above.
E
The beta distribution is used in project management to: A) calculate slack on activities not on the critical path. B) calculate the probability that a project will be completed within its budget. C) calculate pessimistic and optimistic activity times. D) determine which activity should be crashed. E) none of the above
E
The control of projects involves close monitoring of which of the following? A) resources B) costs C) quality D) budgets E) all of the above
E
The difference between AON and AOA networks is that: A) AOA networks sometimes require dummy activities. B) nodes consume no resources or time in AOA networks. C) both are acceptable in practice; however, Microsoft Project uses AON. D) nodes designate activities in AON, while arrows designate activities in AOA. E) All of the above are true.
E
The main difference between PERT and CPM is that: A) PERT is more accurate than CPM. B) PERT assumes that activity durations are known. C) PERT ignores activity costs. D) CPM assumes activity durations can vary. E) PERT employs three time estimates for each activity.
E
What was the name of the construction project to rebuild the Pentagon after the terrorist attacks on Sept. 11, 2001? A) Project Panther B) Project Pit Bull C) Project Python D) Project Piranha E) Project Phoenix
E
Which of the following statements regarding Bechtel is true? A) Its competitive advantage is project management. B) Bechtel was the construction contractor for the Hoover Dam. C) While helping to rebuild Iraq, Bechtel's crews had to travel under armed escort. D) Bechtel's procurement program is global in nature. E) All of the above are true.
E
A project organization works best for an organization when the project resides in only one of its functional areas.
False
PERT, but not CPM, has the ability to consider the precedence relationships in a project.
False
The PERT pessimistic time estimate is an estimate of the minimum time an activity will require.
False
The fundamental difference between PERT and CPM is that PERT uses the beta distribution for crashing projects while CPM uses cost estimates.
False
The shortest of all paths through the network is the critical path.
False
The standard deviation of project duration is the average of the standard deviation of all activities on the critical path.
False
Work breakdown structure is a useful tool in project management because it addresses the timing of individual work elements.
False
Identify the responsibilities of project managers.
Project managers are directly responsible for making sure that (1) all necessary activities are finished in proper sequence and on time; (2) the project comes in within budget; (3) the project meets its quality goals; and (4) the people assigned to the project receive the motivation, direction, and information needed to do their jobs.
Identify each of the purposes of project scheduling.
Project scheduling shows the relationship of each activity to others and to the whole project. It identifies the precedence relationship among activities. It encourages the setting of realistic time and cost estimates for each activity. It helps make better use of people, money, and material resources by identifying critical bottlenecks in the project.
Describe the differences between a Gantt chart and a PERT/CPM network.
The differences between a Gantt chart and a PERT/CPM network are mainly that PERT/CPM has the ability to consider precedence relationships and interdependence of activities.
How is the expected completion time of a project activity, and of a PERT project, computed?
The expected completion time of a project activity uses the beta distribution; expected time is the weighted average of optimistic, most likely, and pessimistic time estimates. The formula is t = (a + 4m + b) / 6. Expected completion of a PERT project is the sum of the expected times for individual activities that are on the critical path.
What are the three phases of a project? Describe each in a sentence or two.
The three phases are planning, scheduling, and controlling. Planning includes goal setting, defining the project, and team organization. Scheduling relates people, money, and supplies to specific activities and relates activities to each other. Controlling is where the firm monitors resources, costs, quality, and budgets. It also revises or changes plans and shifts resources to meet time and cost demands.
What are some of the ethical issues faced by project managers?
gifts from contractors, pressure to mask delays with false status reports, falsifying (exaggerating) expense reports, and compromising quality with substandard materials or practices to meet bonuses or avoid penalties related to schedules.
Ethical issues that can arise in projects include gifts from contractors, pressure to mask delays with false status reports, and pressure to compromise project quality to meet bonuses or avoid penalties related to schedules.
True
Every network has at least one critical path.
True
Gantt charts give a timeline for each of a project's activities, but they do not adequately illustrate the interrelationships between the activities and the resources.
True
In PERT analysis, the identification of the critical path can be incorrect if a noncritical activity takes substantially more than its expected time.
True
In project management, crashing an activity must consider the impact on all paths in the network.
True
One responsibility of a project manager is to make sure that the project meets its quality goals.
True
Project managers have their own code of ethics, established by the Project Management Institute.
True
Slack is the amount of time an activity can be delayed without delaying the entire project.
True
The ES of an activity that has only one predecessor is simply the EF of that predecessor.
True
The critical path can be determined by use of either the "forward pass" or the "backward pass."
True
