Which of the following is best project management tool to use to determine the longest time the project will take?

A PERT chart, sometimes called a PERT diagram, is a project management tool used to schedule, organize and coordinate tasks within a project. It provides a graphical representation of a project's timeline that enables project managers to break down each individual task in the project for analysis.

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Terminology
How a PERT chart works
When to use a PERT chart
Advantages of PERT charts
Disadvantages of PERT charts
PERT chart vs. Gantt chart

The PERT chart template uses nodes -- drawn as rectangles or circles -- to represent events and milestones throughout the project. The nodes are connected by vectors -- drawn as lines -- which represent the various tasks that need to be completed.

PERT charts provide project managers with an estimation of the minimum amount of time needed to complete a project. Managers can also analyze the work breakdown and task connections, as well as assess the risk associated with the project. The breakdown structure makes it easy to organize a complex project with a variety of moving parts by visualizing the dependencies between each step of the process.

PERT stands for Program Evaluation Review Technique, a methodology developed by the U.S. Navy in the 1950s to manage the Polaris submarine missile program. A similar methodology, the critical path method (CPM) was developed for project management in the private sector at about the same time.

Terminology

Here is a list of terms associated with PERT charts:

Nodes are visual representations of milestones or events within the project. They are drawn as either numbered boxes or numbered circles.
Arrows are visual representations of the tasks that occur throughout the project. The direction of the arrow indicates the sequence of the task. Diverging arrows show that various tasks can be completed at the same time.
Fast tracking is when tasks and activities are performed simultaneously.
A PERT event is the point at which one or more tasks are started or completed.
A predecessor event occurs immediately before some events. A successor event naturally occurs after events.
Slack is the amount of time a single task can be delayed without harming other tasks or the project as a whole.
The critical path is the longest -- or most time-consuming -- path from the start to the completion of an event or task.
Critical path activity refers to a task that does not experience slack.
Crashing critical path is when the completion time of a task is shortened.
Lag time refers to the earliest point at which a task can follow another.
Lead time is the amount of time it should take to complete a task without impacting the following activities.
Expected time is the best estimation of how long a task will take to complete, taking into consideration any problems or obstacles that might arise.
Optimistic time refers to the minimum amount of time it will take to complete a task.
Pessimistic time is the maximum amount of time it will take to finish a task.
Most likely time is the best guess of how long a task will take, assuming no problems arise.

How a PERT chart works

A PERT chart presents a graphic illustration of a project as a network diagram consisting of numbered nodes linked by labeled vectors. The direction of the arrows on the lines indicates the sequence of tasks.

When creating a PERT chart, project managers should follow the below steps:

Define all activities involved in the project.
Consider any dependencies between tasks.
Draw nodes and arrows based on the information gathered in the first two steps.
Identify the completion time for each task.

Once the PERT chart is drawn, project managers can use it to develop a realistic time frame for the project:

This can be done by finding the longest path, based on the estimations entered. This path should include the tasks that take the longest to complete.
By adding together the time it takes to complete each task, an estimation will be provided for how long the entire project will take.
Once this is done, the PERT chart can then be used to adjust the times if circumstances change or to ensure the project is finished by its designated deadline.

A breakdown of a PERT chart

In the diagram, for example, the tasks between nodes 1, 2, 4, 8 and 10 must be completed in sequence. These are called dependent or serial tasks. The tasks between nodes 1 and 2 and nodes 1 and 3 are not dependent on the completion of one to start the other and can be undertaken simultaneously. These tasks are called parallel or concurrent tasks.

Tasks that must be completed in sequence but that don't require resources or completion time are considered to have event dependency. These are represented by dotted lines with arrows and are called dummy activities. For example, the dashed arrow linking nodes 6 and 9 indicates that the system files must be converted before the user test can take place but that the resources and time required to prepare for the user test -- writing the user manual and user training -- are on another path. Numbers on the opposite sides of the vectors indicate the time allotted for the task.

When to use a PERT chart

PERT charts should be used when a project manager needs to:

determine the project's critical path in order to guarantee all deadlines are met;
display the various interdependencies of tasks;
estimate the amount of time needed to complete the project; and
prepare for more complex and larger projects.

Project managers find best results when they use a PERT chart at the beginning of the project. Doing so helps ensure the project is accurately scoped and can help avoid any potential bottlenecks in the process.

Advantages of PERT charts

Project managers use PERT charts to gain these benefits:

The PERT technique provides the ability to evaluate the time and resources necessary to a project by tracking required assets at each stage of the process, as well as throughout the course of the project.
PERT charts are useful in what-if analyses, helping companies understand all possible workflows and choose the most efficient and beneficial path.
The analysis of the PERT chart includes data from various departments within an organization. Combining all of the information helps identify each responsible team within the company, while facilitating an environment where each department takes responsibility for its work.
The process of creating a PERT chart also improves communication and enables an organization to invest energy in projects that will enhance its strategic positioning.
PERT charts make unclear deadlines more predictable, clarify dependencies between tasks and establish a clear order for completing the tasks.

Disadvantages of PERT charts

Disadvantages of the PERT chart include the following:

A strict focus on deadlines may not enable managers to see the full financial positioning of the project.
PERT charts lack the flexibility to adapt to small changes that occur when confronted with a roadblock.
If any calculations are inaccurate in the creation of the chart, delays could occur, causing bottlenecks and negatively impacting the final delivery date.
PERT charts are subjective; their success depends on the experience of the project manager. Consequently, some charts may include unreliable data or unrealistic expectations for the cost and time frame of the project.
Creating a PERT chart is labor-intensive, requiring additional time and resources. Also, in order for the chart to remain valuable, it must be consistently reviewed and maintained.

PERT chart vs. Gantt chart

The PERT chart is sometimes preferred over the Gantt chart, another popular visual tool for project managers, because it clearly illustrates task dependencies. On the other hand, the PERT chart can be more difficult to interpret, especially on complex projects. Frequently, project managers use both techniques.

Both PERT and Gantt charts help simplify the project management process through a breakdown structure that divides the project into smaller tasks and identifies any constraints, thus enabling managers to increase efficiencies and view the project as a whole. Another similarity is the use of both charts to identify dependencies and improve time management.
While PERT charts are best used before a project begins to plan and estimate how long each task will take, Gantt charts are best used while a project is running. Throughout the project, managers use Gantt charts to schedule tasks by date and visualize the amount of completed work. In a Gantt chart, each task is represented by a long bar that connects the starting point of the task to its end date.

  To control the schedule, a project manager is reanalyzing the project to predict project duration. She does this by analyzing the sequence of activities with the least amount of scheduling flexibility. What technique is she using?

C.     Precedence diagramming

D.    Work breakdown structure

2.      A dependency requiring that design be completed before manufacturing can start is an example of a(n):

A.    Discretionary dependency.

3.      Which of the following are GENERALLY illustrated BETTER by bar charts than network diagrams?

4.      If the optimistic estimate for an activity is 12 days, and the pessimistic estimate is 18 days, what is the standard deviation of this activity?

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5.      A heuristic is BEST described as a:

A.    The amount of time an activity can be delayed without delaying the project finish date.

B.     The amount of time an activity can be delayed without delaying the early start date of its successor.

D.    The product of a forward and backward pass.

7.      Which of the following is the BEST project management tool to use to determine the longest time the project will take?

A.    Work breakdown structure

8.      Which of the following is CORRECT?

A.    The critical path helps prove how long the project will take.

B.     There can be only one critical path.

C.     The network diagram will change every time the end date changes.

D.    A project can never have negative float.

9.      What is the duration of a milestone?

A.    It is shorter than the duration of the longest activity.

B.     It is shorter than the activity it represents.

D.    It is the same length as the activity it represents.

10. Which of the following BEST describes the relationship between standard deviation and risk?

A.    There is no relationship.

B.     Standard deviation tells you if the estimate is accurate.

C.     Standard deviation tells you how uncertain the estimate is.

D.    Standard deviation tells you if the estimate includes a pad.

11. The float of an activity is determined by:

A.    Performing a Monte Carlo analysis.

B.     Determining the waiting time between activities.

D.    Determining the length of time the activity can be delayed without delaying the critical path.

12. A project has three critical paths. Which of the following BEST describes how this affects the project?

A.    It makes it easier to manage.

B.     It increases the project risk.

C.     It requires more people.

D.    It makes it more expensive.

13. If project time and cost are not as important as the number of resources used each month, which of the following is the BEST thing to do?

A.    Perform a Monte Carlo analysis.

B.     Fast track the project.

C.     Perform resource leveling.

D.    Analyze the life cycle costs.

14. When would a milestone chart be used instead of a bar chart?

B.     Reporting to team members

C.     Reporting to management

15. Your project management plan results in a project schedule that is too long. If the project network diagram cannot change but you have extra personnel resources, what is the BEST thing to do?

A.    Fast track the project.

D.    Perform Monte Carlo analysis.

16. Which of the following is the BEST thing to do to try to complete a project two days earlier?

A.    Tell senior management that the projects critical path does not allow the project to be finished earlier.

C.     Meet with the team to look at options for crashing or fast tracking the critical path.

D.    Work hard and see what the project status is next month.

17. In attempting to complete the project faster, the project manager looks at the cost associated with crashing each activity. The BEST approach to crashing would also include looking at the:

A.    Risk impact of crashing each activity.

B.     Customer’s opinion of which activities to crash.

C.     Boss’s opinion of which activities to crash and in which order.

D.    Project life cycle phase in which the activity is due to occur.

18. Which of the following processes includes asking team members about the time estimates for their activities and reaching agreement on the calendar date for each activity?

D.    Develop Project Charter

19. A project manager is in the middle of executing of a very large construction project when he discovers the time needed to complete the project is longer than the time available. What is the BEST thing to do?

B.     Meet with management and tell them the required date cannot be me
t.

D.    Determine options for schedule compression and present management with his recommended option.

20. During project planning, you estimate the time needed for each activity and then add the estimates to create the project estimate. You commit to completing the project by this date. What is wrong with this scenario?

A.    The team did not create the estimate, and estimating takes too long using that method.

B.     The team did not create the estimate, and a network diagram was not used.

C.     The estimate is too long and should be created by management.

D.    The project estimate should be the same as the customer’s required completion date.

21. You are a project manager on a US $5,000,000 software development project. While working with your project team to develop a network diagram, you notice a series of activities that can be worked in parallel but must finish in a specific sequence. What type of activity sequencing method is required for these activities?

A.    Precedence diagramming method

B.     Arrow diagramming method

D.    Operational diagramming method

22. You are a project manager on a US $5,000,000 software development project. While working with your project team to develop a network diagram, your data architects suggest that quality could be improved if the data model is approved by senior management before moving on to other design elements. They support this suggestion with an article from a leading software development journal. Which of the following BEST describes this type of input?

B.     Discretionary dependency

23. Based on the following, if you needed to shorten the duration of the project, what activity would you try to shorten?

24. You have a project with the following activities: Activity A takes 40 hours and can start after the project starts. Activity B takes 25 hours and should happen after the project starts. Activity C must happen after activity A and takes 35 hours. Activity D must happen after activities B and C and takes 30 hours. Activity E must take place after activity C and takes 10 hours. Activity F takes place after Activity E and takes 22 hours. Activities F and D are the last activities of the project. Which of the following is TRUE if activity B actually takes 37 hours?

A.    The critical path is 67 hours.

B.     The critical path changes to Start, B, D, End.

C.     The critical path is Start, A, C, E, F, End.

D.    The critical path increases by 12 hours.

25. A project manager has received activity duration estimates from his team. Which of the following does he need in order to complete the Develop Schedule process?

B.     Schedule change control system

C.     Recommended corrective actions

26. A project manager is taking over a project from another project manager during project planning. If the new project manager wants to see what the previous project manager planned for managing changes
to the schedule, it would be BEST to look at the:

A.    Communications management plan.

B.     Update management plan.

C.     Staffing management plan

D.    Schedule management plan.

27. A project manager is using weighted average duration estimates to perform schedule network analysis. Which type of mathematical analysis is being used?

28. The WBS, estimates for each work package, and the network diagram are completed. Which of the following would be the NEXT thing for the project manager to do?

A.    Sequence the activities.

B.     Verify that they have the correct scope.

C.     Create a preliminary schedule and get the teams approval.

D.    Complete risk management.

29. A new product development project has four levels in the work breakdown structure and has been sequenced using the precedence diagramming method. The activity duration estimates have been received. What should be done NEXT?

A.    Create an activity list.

B.     Begin the work breakdown structure.

C.     Finalize the schedule.

D.    Compress the schedule.

30. You are the project manager for a new product development project that has four levels in the work breakdown structure. The network diagram and duration estimates have been created, and a schedule has been developed and compressed. What time management activity should you do NEXT?

B.     Estimate Activity Resources.

C.   �
� Analogously estimate the schedule.

31. A team member from research and development tells you that her work is too creative to provide you with a fixed single estimate for the activity. You both decide to use the average labor hours per installation from past projects to predict the future. This is an example of which of the following?

B.     Three-point estimating

32. An activity has an early start (ES) of day 3, a late start (LS) of day 13, an early finish (EF) of day 9, and a late finish (LF) of day 19. The activity:

A.    Is on the critical path.

D.    Is not on the critical path.

33. The project is calculated to be completed four days after the desired completion date. You do not have access to additional resources. The project is low risk, the benefit cost ratio (BCR) is expected to be 1.6, and the dependencies are preferential. Under these circumstances, what would be the BEST thing to do?

A.    Cut resources from an activity.

B.     Make more activities concurrent.

C.     Move resources from the preferential dependencies to the external dependencies.

D.    Remove an activity from the project.

34. A project manager for a small construction company has a project that was budgeted for US $130,000 over a six-week period. According to her schedule, the project should have cost US $60,000 to date. However, it has cost US $90,000 to date. The project is also behind schedule, because the original estimates were not accurate. Who has the PRIMARY responsibility to solve this problem?

D.    Manager of the project management office

35. Senior management is complaining that they are not able to easily determine the status of ongoing projects in the organization. Which of the following types of reports would help provide summary information to senior management?

A.    Detailed cost estimates

B.     Project management plans

36. Rearranging resources so that a constant number of resources is used each month is called:

37. Which of the following is a benefit of an analogous project estimate?

A.    It will be closer to what the work will actually require.

B.     It is based on a detailed understanding of what the work requires.

C.     It gives the project team an understanding of management’s expectations.

D.    It helps the project manager determine if the project will meet the schedule.

38. During project executing, a large number of changes are made to the project. The project manager should:

A.    Wait until all changes are known and print out a new schedule.

B.     Make approved changes as needed, but retain the schedule baseline.

C.     Make only the changes approved by management.

D.    Talk to management before any changes are made.

Explanation There are only two choices related to scheduling; critical path method and precedence diagramming. Precedence diagramming, however, is a diagramming technique that deals with the relationship between activities, not schedule flexibility. The project manager is analyzing the critical path.

Explanation No mention is made that the dependency comes from a source outside the project, so this is not an external dependency. Scope dependency is not a defined term. The key word in the question is “requires.” Since the dependency is required, it could not be discretionary and therefore must be mandatory. The question defines a mandatory dependency.

Explanation The bar chart (or Gantt chart) is designed to show a relationship to time. This is best used when demonstrating progress or status as a factor of time.

Explanation The standard deviation is computed by [P – O]/6. Therefore, the answer is [18 — 12]/6 = 6/6 = 1.

Explanation A heuristic is a rule of thumb. Examples ar e cost per line of code, cost per square foot of floor space, etc.

Explanation Total float and free float are the time an activity can be delayed without impacting the entire project or the next activity. A forward or backward pass refers to a network analysis technique, not waiting time. Waiting time is the correct definition of lag.

Explanation The bar chart may show an end date, but it is not used to determine dates. The project charter also may include a required end date, but not a logical determination of how long the project will take. The network diagram takes the work packages from the work breakdown structure and adds dependencies. The dependencies allow us to look at the various paths through the diagram to determine the longest duration (critical) path. The network diagram is the best answer.

Explanation This question tests your knowledge about a number of topics. There can often be more than one critical path, but you might adjust the plan in order to decrease risk and have only one critical path. The network diagram may or may not change when the end date changes, depending on the amount of schedule reserve and the reason for the change to the schedule. You can have negative float if you are behind schedule. The critical path helps prove how long the project will take. This is the only correct statement of the choices given.

Explanation A milestone shows the completion of a series of activities or work packages. Therefore, it takes no time of its own.

Explanation An estimate can have a wide range and still be accurate if the item estimated includes identified risks. There is no such thing as a pad in proper project management. An estimate might be inflated, but it is a calculated reserve to account for risks, not arbitrary padding. The standard deviation tells you the amount of uncertainty or risk involved in the estimate for the activity.

Explanation The float of an activity is the length of time the activity can be delayed without delaying the critical path.

Explanation Though having three critical paths COULD require more people or cost more, the answer that is definitely and always true is that it increases project risk. Because you need to manage three critical paths, there is more risk that something could happen to delay the project.

Explanation Fast tracking affects both time and cost but may not help even out resource usage. Monte Carlo analysis and analysis of life cycle costs do not directly deal with resources. Leveling is the only choice that will definitely affect resources.

Explanation Both types of charts are used in project planning. Team members need to see details and so they need a bar chart rather than a milestone chart. Risk analysis COULD make use of both charts. A milestone chart is used instead of a bar chart for any situation where you want to report in a less detailed way. Since bar charts can scare people with their complexity and often show too much detail to be worthwhile on a management level, milestone charts are more effective for reporting to management.

Explanation Leveling resources generally extends the schedule. Monte Carlo analysis does not directly address the constraints of this situation. To compress the schedule, you could either crash or fast track. However, the situation says that the network diagram cannot change. This eliminates the fast tracking option, leaving crashing the project as the best answer.

Explanation This is another question that asks about problem solving. Telling the boss or waiting to see the status next month do not try to solve the real problem. It would be inaccurate to report that the project cannot be finished earlier. Only meeting with the team to look for options for crashing or fast tracking the critical path relates to problem solving.

Explanation You may or may not need your customers or your boss’s input, but you will definitely need to include an analysis of risk.

Explanation By the time this process is taking place, Develop Project Charter, Sequence Activities, and Define Scope and would be completed. The team members would have provided estimates in the Estimate Activity Durations process, but the project manager may talk to them about those estimates as part of developing the project schedule. The process defined in the question is Develop Schedule.

Explanation This question again tests whether you know how to solve problems. Cutting product scope negatively affects the customer, and is therefore not best. A project manager’s job is to determine options for meeting any end date; therefore, simply telling management the required date cannot be met is not correct. Working overtime is expensive and unnecessary when there are many other choices that could be selected first. Determining options for schedule compression would have the least negative effect on the project.

Explanation Time estimates for the activities should be created by the team and should not be added together to create the project estimate. Some activities may take place concurrently; these would be identified in the network diagram.

Explanation The question implies a finish-to-finish relationship between activities. The arrow diagramming method does not support that type of relationship. Critical path is not a diagramming method, and operational diagramming method is a made-up term. The precedence diagramming method is most appropriate in this case.

Explanation The situation is neither mandatory nor driven by an external source. A heuristic is a rule of thumb that can be used consistently. This situation is a unique occurrence for which a preferred method is being suggested. Therefore, this is a discretionary dependency.

Explanation This is an example of a two-stage question you may find on the exam. First you need to draw the network diagram and find the critical path, and then make a decision. The network diagram would be:

The critical path is 16 (Start, C, E, H, End). Many people immediately look for the longest duration activity on the project to cut. Here activity D is the longest, at 10 weeks. However, that activity is not on the critical path, and cutting it would not shorten the project’s duration. You must change the critical path. In this case, both activity C and activity H are on the critical path. If you have a choice, all things being equal, choose the earlier option. Therefore, activity C is the best answer.

Explanation Did you notice how difficult this question was to read? Such wording is intentional, to prepare you for interpreting questions on the real exam. Looking at this situation, you see there are three paths through the network as shown in the following table. If the duration of activity B changes from 25 to 37, the activity will take 12 hours longer. As the activity is only on the third path, it will only change the duration of that path from 55 to 55 + 12, or 67 hours. Since the duration of the critical path is 107 hours, the delay with activity B will have no impact on the project timeline or the current critical path.

Explanation The Develop Schedule process includes all work and uses all inputs needed to’ come up with a finalized, realistic schedule. Reserves are created to cover identified and unknown schedule risks. All the other items are parts of Control Schedule and occur after the Develop Schedule process.

Explanation The schedule management plan is the most correct answer. It is created as part of the Develop Project Management Plan process and is the repository for plans for schedule changes.

Explanation PERT uses weighted averages to compute activity durations.

Explanation Sequencing the activities is the same thing as creating a network diagram, so that has already been done. The Verify Scope process is done during project monitoring and controlling, not during project planning. Since a schedule is an input to risk management, risk management comes after the creation of a preliminary schedule, and so that is not the “next thing to do.” Creating the preliminary schedule is next.

Explanation The question is really asking, “What is done after the Estimate Activity Durations process?” The work breakdown structure and activity list are done before Estimate Activity Durations. The schedule is not finalized until after schedule compression. Therefore compressing the schedule is done next.

Explanation Notice how this question and the previous one seem very similar. This is intended to prepare you for similar questions on the exam. Estimating activity resources and analogously estimating the schedule should have already been completed. The situation described is within the Develop Schedule process of time management. Control Schedule is the next time management process after Develop Schedule, but the Develop Schedule process is not yet finished. Final approval of the schedule by the stakeholders is needed before one has a project schedule.

Explanation Monte Carlo relates to what-if analysis. Three-point estimating uses three time estimates per activity. One could use data from past projects to come up with the estimate (analogous estimating) but the best answer is parametric estimating because past history is being used to calculate an estimate. An estimate such as hours per installation is a characteristic of this form of estimating.

Explanation There is no information presented about lag or progress. The activity described has float, because there is a difference between the early start and late start. An activity that has float is probably not on the critical path.

Explanation Cutting resources from an activity would not save time, nor would moving resources from the preferential dependencies to the external dependencies. Removing an activity from the project is a possibility, but since the dependencies are preferential and the risk is low, the best choice would be to make more activities concurrent, as this would have less impact on the project.

Explanation Did you get lost looking at all the numbers presented in this question? Notice that there are no calculations required, simply an understanding of what the problem is. This question describes schedule management, which is a responsibility of the project manager.

Explanation Detailed cost estimates have nothing to do with the situation described. Project management plans include more detail than is necessary for the situation described, and may distract from the conversation if used in this situation. Bar charts are most effective for reporting to the team. The best answer is milestone reports, which present the right level of detail for upper management.

Explanation The key to this question is the phrase “constant number used each month.” Only leveling has such an effect on the schedule.

Explanation Remember for the exam that analogous estimates are considered to be top-down, high-level estimates. Therefore, they are not based on a detailed understanding of what the work will require. The project manager needs more than an analogous (high-level) estimate to determine whether or not the project will meet the schedule. The benefit of an analogous project estimate is that it is managements expectations of what the project will cost. Any differences between the analogous estimate and the detailed bottom-up estimate can be reconciled in the planning processes.

Explanation Waiting until all changes are known, and then printing out a new schedule, is a common error many project managers make. Instead, the project manager should be controlling the project throughout its completion. The situation in the question does not provide a reason to believe the schedule baseline must be changed. A project manager must be in control of the project, rather than consulting with management before making any changes. Whenever a large number of changes occur on a project, it is wise to confirm that the business case, as stated in the project charter, is still valid.