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.

What are some of the ethical issues faced by project managers?

A project manager can be exposed to a wide variety of ethical issues. These include, but are not limited to, 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.

What is a project organization?

A project organization is an organization formed to ensure that programs (projects) receive the proper management and attention.

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

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

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

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

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

12) Match the following steps in Microsoft's development of Windows 8 to their respective WBS level. Step Level Develop Windows 8 Operating System ? System Testing ? Compatible with Windows 7 ? Develop GUI's ? Module Testing ?

A) Level 1, Level 2, Level 4, Level 3, Level 3

A project manager is interested in crashing a project with variable activity times. Which of the following tools should he/she employ?

A) PERT

A simple CPM network has three activities, A, B, and C. A is an immediate predecessor of B and of C. B is an immediate predecessor of C. The activity durations are A=4, B=3, C=8.

A) The critical path is A-B-C, duration 15.

A simple CPM network has three activities, D, E, and F. D is an immediate predecessor of E and of F. E is an immediate predecessor of F. The activity durations are D=4, E=3, F=8.

A) The critical path is D-E-F, duration 15.

Which of the following statements regarding PERT times is true?

A) The optimistic time estimate is an estimate of the minimum time an activity will require.

A code of ethics especially for project managers:

A) has been established by the Project Management Institute.

A project organization:

A) is effective for companies with multiple large projects.

The phases of project management are:

A) planning, scheduling, and controlling.

Describe in words how to calculate a project's standard deviation. What assumption allows that calculation to be accurate?

Add the variances of the activities on the critical path and then take the square root. We can do this because we assume that the activities are independent.

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?

B) 0.0228

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?

B) 0.3446

A project whose critical path has an estimated time of 120 days with a variance of 100 has a 20% chance that the project will be completed before which day (rounded to nearest day)?

B) 112

An activity on a PERT network has these time estimates: optimistic = 1, most likely = 2, and pessimistic = 5. What is its expected activity time?

B) 2.33

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

B) 5.33

Which of the following statements about Bechtel is true?

B) Bechtel is the world's premier manager of massive construction and engineering projects.

The ________ distribution is used by PERT analysis to calculate expected activity times and variances.

B) Beta

Which of the following statements regarding time-cost tradeoffs in CPM networks is false?

B) Crashing sometimes has the reverse result of lengthening the project duration.

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?

B) There are four paths in this network.

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

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

A project organization that becomes permanent is often referred to as a:

B) matrix organization.

The time an activity will take assuming very unfavorable conditions is:

B) the pessimistic time.

The expected activity time in PERT analysis is calculated as:

B) the weighted average of a, m, and b, with m weighted 4 times as heavily as a and 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?

C) 0.1587

A project whose critical path has an estimated time of 820 days with a variance of 225 has a 20% chance that the project will be completed before which day (rounded to nearest day)?

C) 807

Which of the following statements regarding Gantt charts is true?

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

The project organization works best when which of the following conditions are satisfied? I. Work tasks can be defined with a specific goal and deadline. II. The job is typical and familiar to the existing organization. III. The work contains interrelated tasks requiring specialized skills. IV. The project is temporary but unimportant to long-term organizational success. V. The project cuts across organizational lines.

C) I, III, V

Which of the following is NOT a limitation of PERT?

C) Only one time estimate can be used for each activity.

Which of the following statements regarding PERT times is true?

C) The expected time estimate is calculated as t = (a + 4m + b)/6.

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?

C) The set of times cannot all be possible.

The beta distribution is used in project management to:

C) calculate expected activity times.

Which of the following is NOT performed by Microsoft Project?

C) providing PERT probability calculations

________ is decreasing activity time in a network to reduce time on the critical path so total completion time is reduced.

Crashing

What is the objective of critical path analysis?

Critical path analysis determines the longest path through a network of activities. This longest path is the key to making the schedule that provides for completing all activities in the shortest time. Critical path analysis identifies those activities critical to timely completion of all activities so they can receive management focus.

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?

D) 0.4773

Contract requirements state that a project must be completed within 180 working days, or it will incur penalties for late completion. Analysis of the activity network reveals an estimated project time of 145 working days with a project variance of 400. What is the probability that the project will be completed before the late-payment deadline?

D) 0.9599

Which of the following statements regarding CPM is true?

D) All activities on the critical path have their LS equal to the maximum EF of all immediate predecessors.

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

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

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?

D) D is critical, and has zero slack.

Which of the following statements regarding CPM networks is true?

D) If a specific project has multiple critical paths, all of them will have the same duration.

Which of the following statements regarding critical paths is true?

D) On a specific project, there can be multiple critical paths, all with exactly the same duration.

Which of the following statements regarding PERT analysis is true?

D) Only critical activities contribute to the project variance.

Which of the following statements concerning CPM activities is false?

D) The late finish of an activity is the earliest late start of all preceding activities.

Which of the following is NOT one of the phases of project management?

D) budgeting

A network has been crashed to the point where all activities are critical. Additional crashing:

D) may require crashing multiple tasks simultaneously.

WBS stands for which of the following project management tools?

D) work breakdown structure

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:

E) 118.

The difference between AON and AOA networks is that:

E) All of the above are true.

Which of the following statements regarding Bechtel is true?

E) All of the above are true.

Which of the following projects were completed by Bechtel?

E) All of the above were Bechtel projects

The main difference between PERT and CPM is that:

E) PERT employs three time estimates for each activity.

What was the name of the construction project to rebuild the Pentagon after the terrorist attacks on Sept. 11, 2001?

E) Project Phoenix

The control of projects involves close monitoring of which of the following?

E) all of the above

Ethical issues that may arise in projects large and small include:

E) all of the above.

The beta distribution is used in project management to:

E) none of the above

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

Shortening the project's duration by deleting unnecessary activities is called "project crashing."

False

The PERT pessimistic time estimate is an estimate of the minimum time an activity will require.

False

The critical path can be determined by use of either the "forward pass" or the "backward pass."

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

The network analysis method that allows activity times to vary is ________.

PERT or Program Evaluation and Review Technique

Describe some of the challenges faced in the construction of the new 11-story building at Arnold Palmer Hospital in Orlando, Florida.

Prior to beginning actual construction, regulatory and funding issues added, as they do with most projects, substantial time to the overall project. Cities have zoning and parking issues, the EPA has drainage and waste issues, and regulatory authorities have their own requirements, as do issuers of bonds.

The ________ has established a code of ethics especially for project managers.

Project Management Institute

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.

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

Slack Time

Define slack time.

Slack time is the length of time an activity can be delayed without delaying the entire project.

PERT calculations typically include the duration variance of each activity. What is the purpose of this calculation, i.e. what's the role of variances in PERT analysis?

The activity variances influence the probability of project completion. Specifically, the sum of the variances of the critical tasks equals the variance of the project. Further, large variances on noncritical tasks need to be monitored. Such an activity might have an actual completion time so large that the task becomes a critical task.

Identify several advantages of using PERT (and CPM).

The advantages include (1) its usefulness for scheduling and controlling large projects, (2) its straightforward concept, (3) its graphical displays of relationships among activities, (4) its critical path and slack time analyses, (5) its ability to document processes, (6) its wide range of applicability, (7) and its usefulness in monitoring schedules and costs.

What is the basic difference between PERT and CPM?

The basic difference between PERT and CPM is that PERT requires three time estimates of activity completion time, whereas CPM uses only a single estimate.

Explain why the critical path is the longest, not the shortest, path through a network.

The critical path is that set of activities in a project network that controls the duration of the entire project. The controlling element to completion of all activities is the longest path; any shorter path will not allow for all activities to be completed.

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.

What are the earliest activity start time and latest activity start time, and how are they computed?

The earliest start time (ES) is the earliest time at which an activity may start and still satisfy all precedence requirements. ES = Max{EF of all immediate predecessors}. The latest start time is the latest time at which an activity may start and still satisfy both precedence requirements and the overall project completion time. LS = LF - Activity time.

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.

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 phase of a large project is scheduling.

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 ________ distribution is appropriate for calculating expected activity times and activity variances in PERT networks.

beta

The ________ is the computed longest time path(s) through a network.

critical path

The ________ is a project management technique using only one time factor per activity that enables managers to schedule, monitor, and control large and complex projects.

critical path method or CPM

A(n) ________ is an organization formed to ensure that programs (projects) receive the proper management and attention.

project organization

A(n) ________ divides a project into more and more detailed components.

work breakdown structure or WBS