Project Time Management

Study Hints

The Project Time Management questions on the PMP® certification exam focus heavily on the program evaluation and review technique (PERT), the critical path method (CPM), the precedence diagramming method (PDM), and the critical chain method; the differences between these four techniques; and the appropriate circumstances for their use. The exam tests your knowledge of how PERT/CPM networks are constructed, how schedules are computed, what the critical path is, and how networks are used to analyze and solve project scheduling, and resource allocation and leveling issues. There is a good chance that you will be presented with a network diagram that will be the subject of five or more questions. Therefore, detailed knowledge of network scheduling is essential. There also seems to be a focus on fast tracking as a method to accelerate the project schedule. You must know the advantages offered by networks over bar charts and network diagrams. You also should understand the concept of float (or slack) and how it presents challenges and opportunities to project schedulers.

Because a thorough understanding of networks and scheduling is required to successfully answer questions on Project Time Management, you should take a course relating to that topic. If you cannot take a course, you may want to consult the user’s manual for one of the more popular desktop software project management packages. Typically, you will find plenty of illustrations and short, easy-to-understand scheduling exercises at the level of detail required to correctly answer the exam questions. Another useful reference is PMI®’s Practice Exam for Scheduling—Second Edition (2011).

The PMBOK® Guide separates the function of Project Time Management into seven processes: plan schedule management, define activities, sequence activities, estimate activity resources, estimate activity durations, develop schedule, and control schedule. Review PMBOK® Guide Figure 6-1 before taking the practice test. Know this chart thoroughly.

Following is a list of the major Project Time Management topics. Use it to help focus your study efforts on the areas most likely to appear on the exam.

Major Topics

Schedule management plan

Define activities

• Activity list
• Activity attributes
• Milestone list

Sequence activities

• PDM
• Dependencies
• Leads and lags
• Project schedule network diagrams

Estimate activity resources

• Expert judgment
• Alternative analysis
• Published estimating data
• Bottom-up estimating
• Activity resource requirements
• Resource breakdown structure
• Resource calendars

Estimate activity durations

• Expert judgment
• Analogous estimating
• Parametric estimates
• Three-point estimates
• Reserve analysis
• Group decision-making techniques
• Activity duration estimates

Develop schedule

• Schedule network analysis
• Critical path method
• Critical chain method
• Resource optimization techniques
• Leads and lags
• Crashing and fast-tracking
• Project schedule
• Schedule baseline
• Project calendars

Control schedule

• Performance reviews
• Work performance information
• Change requests
• Updates
• Project management plan
• Project documents

Practice Questions

INSTRUCTIONS: Note the most suitable answer for each multiple-choice question in the appropriate space on the answer sheet.

Use the following network diagram to answer questions 1 through 4. Activity names and duration are provided.

1. What is the duration of the critical path in this network?
   1. 10
   2. 12
   3. 14
   4. 15
2. What is the float for Activity G?
   5. –2
   6. 0
   7. 1
   8. 4
3. If a project planner imposes a finish time of 14 on the project with no change in the start date or activity durations, what is the total float of Activity E?
   9. –1
   10. 0
   11. 2
   12. Cannot be determined
4. If the imposed finish time in question 3 above is removed and reset to 16 and the duration of Activity H is changed to 3, what is the late finish for Activity G?
   13. –11
   14. 11
   15. –13
   16. 13
5. Your company, which operates one of the region’s largest chemical processing plants, has been convicted of illegally dumping toxic substances into the local river. The court has mandated that the required cleanup activities be completed by February 15. This date is an example of—
   17. A key event
   18. A milestone
   19. A discretionary dependency
   20. An external dependency
6. You are managing a construction project for a new city water system. The contract requires you to use special titanium piping equipment that is guaranteed not to corrode. The titanium pipe must be resting in the ground a total of 10 days before connectors can be installed. In this example, the 10-day period is defined as—
   21. Lag
   22. Lead
   23. Float
   24. Slack
7. Of the following tools and techniques, which one is NOT used for schedule control?
   25. Fast tracking
   26. What-if scenario analysis
   27. Three-point estimates
   28. Adjusting leads and lags
8. You are planning to conduct the team-building portion of your new project management training curriculum out-of-doors in the local park. You are limited to scheduling the course at certain times of the year, and the best time for the course to begin is mid-July. One of the more common date constraints to use as you develop the project schedule is—
   29. “Start no earlier than”
   30. “Finish no earlier than”
   31. “Fixed late start”
   32. “Fixed early finish”
9. Project schedule development is an iterative process. If the start and finish dates are not realistic, the project probably will not finish as planned. You are working with your team to define how to manage schedule changes. You documented your decisions in which of the following?
   33. Schedule change control procedures
   34. Schedule management plan
   35. Schedule risk plan
   36. Service-level agreement
10. If, when developing your project schedule, you want to define a distribution of probable results for each schedule activity and use that distribution to calculate another distribution of probable results for the total project, the most common technique to use is—
    37. PERT
    38. Monte Carlo analysis
    39. Linear programming
    40. Concurrent engineering
11. Your lead engineer estimates that a work package will most likely require 50 weeks to complete. It could be completed in 40 weeks if all goes well, but it could take 180 weeks in the worst case. What is the PERT estimate for the expected duration of the work package?
    41. 45 weeks
    42. 70 weeks
    43. 90 weeks
    44. 140 weeks
12. Your customer wants the project to be completed six months earlier than planned. You believe you can meet this target by overlapping project activities. The approach you plan to use is known as—
    45. Critical chain
    46. Fast tracking
    47. Leveling
    48. Crashing
13. Activity A has a duration of three days and begins on the morning of Monday the 4th. The successor activity, B, has a finish-to-start relationship with A. The finish-to-start relationship has three days of lag, and activity B has a duration of four days. Sunday is a nonworkday. Such data can help to determine—
    49. The total duration of both activities is 8 days
    50. Calendar time between the start of A to the finish of B is 11 days
    51. The finish date of B is Wednesday the 13th
    52. Calendar time between the start of A to the finish of B is 14 days
14. You can use various estimating approaches to determine activity durations. When you have a limited amount of information available about your project, especially when in the early phases, the best approach to use is—
    53. Bottom-up estimating
    54. Analogous estimating
    55. Reserve analysis
    56. Parametric analysis
15. “I cannot test the software until I code the software.” This expression describes which of the following dependencies?
    57. Discretionary
    58. Rational
    59. Preferential
    60. Mandatory or hard
16. Working with your team to provide the basis for measuring and reporting schedule progress, you agree to use the—
    61. Schedule management plan
    62. Network diagram
    63. Project schedule
    64. Technical baseline
17. Your approved project schedule was based on resource leveling because of a scarcity of resources. Management has now mandated that the project be completed as soon as possible. Which of the following methods will you use to recalculate the schedule?
    65. Resource manipulation
    66. Reverse resource allocation
    67. Critical chain scheduling
    68. Resource reallocation
18. Review the following network diagram and table. Of the various activities, which ones would you crash and in what order?

    

    69. A, C, E, and F
    70. A, B, D, and F
    71. A, B, E, and F
    72. C, A, F, and G
19. You are remodeling your kitchen and decide to prepare a network diagram for this project. Your appliances must be purchased and available for installation by the time the cabinets are completed. In this example, these relationships are—
    73. Start-to-finish
    74. Finish-to-start
    75. Start-to-start
    76. Finish-to-finish
20. Decomposition is a technique used for both WBS development and activity definition. Which following statement best describes the role decomposition plays in activity definition as compared to creating the WBS?
    77. Final output is described in terms of work packages in the WBS.
    78. Final output is described as deliverables or tangible items.
    79. Final output is described as schedule activities.
    80. Decomposition is used the same way in scope definition and activity definition.
21. When sequencing project activities in the schedule, all the following are true EXCEPT—
    81. There may be scheduled dates for specific milestones
    82. Every activity is connected to at least one predecessor and at least one successor
    83. Lead or lag time may be required
    84. Necessary sequencing of events may be described by the activity attributes
22. A schedule performance index of less than 1.0 indicates that the—
    85. Project is running behind the monetary value of the work it planned to accomplish
    86. Earned value physically accomplished thus far is 100%
    87. Project has experienced a permanent loss of time
    88. Project may not be on schedule, but the project manager need not be concerned
23. Various tools and techniques are available to sequence activities, and several factors can help to determine which tool or technique to select. When a project manager decides to include sub-networks or a fragment network as part of his or her scheduling technique, what does this decision say about the project?
    89. The work is unique requiring special network diagrams at various stages.
    90. Software that manages resources is available over an existing electronic network.
    91. Several identical or nearly identical series of activities are repeated throughout the project.
    92. Multiple critical paths exist in the project.
24. To meet regulatory requirements, you need to crash your project schedule. Your first step is to compute—
    93. The cost and time slope for each critical activity that can be expedited
    94. The cost of additional resources to be added to the project’s critical path
    95. The time saved in the overall schedule when tasks are expedited on the critical path
    96. Three probabilistic time estimates of PERT for each critical path activity
25. Which one of the following is a key input to the define activities process?
    97. Project management plan
    98. Project scope statement
    99. Project scope baseline
    100. Project charter
26. Unlike bar charts, milestone charts show—
    101. Scheduled start or completion of major deliverables and key external interfaces
    102. Activity start and end dates of critical tasks
    103. Expected durations of the critical path
    104. Dependencies between complementary projects
27. Project managers should pay attention to critical and subcritical activities when evaluating project time performance. One way to do this is to analyze 10 subcritical paths in order of ascending float. This approach is part of—
    105. Variance analysis
    106. Simulation
    107. Earned value management
    108. Trend analysis
28. An activity has an early start date of the 10th and a late start date of the 19th. The activity has a duration of four days. There are no nonworkdays. From the information given, what can be concluded about the activity?
    109. Total float for the activity is nine days.
    110. The early finish date of the activity is the end of the day on the 14th.
    111. The late finish date is the 25th.
    112. The activity can be completed in two days if the resources devoted to it are doubled.
29. In project development, schedule information such as who will perform the work, where the work will be performed, activity type, and WBS classification are examples of—
    113. Activity attributes
    114. Constraints
    115. Data in the WBS repository
    116. Refinements
30. Which of the following is a key input to define activities?
    117. Project management plan
    118. Project scope management plan
    119. Schedule management plan
    120. Project management software
31. The purpose of using what-if analysis in schedule control is to—
    121. Review scenarios to bring the schedule in line with the plan
    122. Document requested changes
    123. Provide additional details as to when the schedule baseline should be updated
    124. Update the activity attributes
32. Several types of float are found in project networks. Float that is used by a particular activity and does NOT affect the float in later activities is called—
    125. Extra float
    126. Free float
    127. Total float
    128. Expected float
33. All the following statements regarding critical chain method are true EXCEPT—
    129. It modifies the schedule to account for limited resources
    130. The first step is to use conservative estimates for activity durations
    131. Duration buffers are added on the critical path
    132. It focuses on managing buffer activity durations
34. You are managing a new technology project designed to improve the removal of hazardous waste from your city. You are in the planning phase of this project and have prepared your network diagram. Your next step is to—
    133. Describe any unusual sequencing in the network
    134. State the number resources required to complete each activity
    135. Establish a project calendar and link it to individual resource calendar
    136. Determine which schedule compression technique is the most appropriate, because your customer requests that the project be completed as soon as possible
35. The risk register may need to be updated as an output of which following process:
    137. Define activities
    138. Sequence activities
    139. Estimate activity resources
    140. Control schedule
36. You are managing a project that will use a virtual team with team members on three different continents. Your company is looking to use the virtual team to provide a lower cost product by using resources in countries that have a favorable exchange rate to that of your country. To assist in this process as you estimate resource requirements, it is helpful to consider—
    141. Bottom-up estimating
    142. Published estimating data
    143. Analogous estimating
    144. Reserve analysis
37. Activity A has a pessimistic (P) estimate of 36 days, a most likely (ML) estimate of 21 days, and an optimistic (O) estimate of 6 days. What is the probability that activity A will be completed in 16 to 26 days?
    145. 55.70 percent
    146. 68.26 percent
    147. 95.46 percent
    148. 99.73 percent
38. You are managing a project to redesign a retail store layout to improve customer throughput and efficiency. Much project work must be done on site and will require the active participation of store employees who are lifelong members of a powerful union with a reputation for labor unrest. One important component of your schedule must be—
    149. A resource capabilities matrix
    150. Buffers and reserves
    151. A resource calendar
    152. A resource histogram
39. To account for uncertainty in a schedule, reserve analysis may be used. All the following are examples of contingency reserves EXCEPT—
    153. Fixed number of work periods
    154. Percent of the estimated activity duration
    155. Buffers
    156. Productivity metrics
40. The reason that the schedule performance index (SPI) is shown as a ratio is to—
    157. Enable a detailed analysis of the schedule regardless of the value of the schedule variance
    158. Distinguish between critical path and noncritical path work packages
    159. Provide the ability to show performance for a specified time period for trend analysis
    160. Measure the actual time to complete the project

Answer Sheet

1.	a	b	c	d
2.	a	b	c	d
3.	a	b	c	d
4.	a	b	c	d
5.	a	b	c	d
6.	a	b	c	d
7.	a	b	c	d
8.	a	b	c	d
9.	a	b	c	d
10.	a	b	c	d
11.	a	b	c	d
12.	a	b	c	d
13.	a	b	c	d
14.	a	b	c	d
15.	a	b	c	d
16.	a	b	c	d
17.	a	b	c	d
18.	a	b	c	d
19.	a	b	c	d
20.	a	b	c	d

21.	a	b	c	d
22.	a	b	c	d
23.	a	b	c	d
24.	a	b	c	d
25.	a	b	c	d
26.	a	b	c	d
27.	a	b	c	d
28.	a	b	c	d
29.	a	b	c	d
30.	a	b	c	d
31.	a	b	c	d
32.	a	b	c	d
33.	a	b	c	d
34.	a	b	c	d
35.	a	b	c	d
36.	a	b	c	d
37.	a	b	c	d
38.	a	b	c	d
39.	a	b	c	d
40.	a	b	c	d

Answer Key

1. d. 15

   The total duration for the path B-C-D-E-I is 15. The duration of any other path in the network is less than 15. [Planning]

Meredith and Mantel 2012, Chapter 8

PMI®, PMBOK® Guide, 2013, 176–177

1. c. 1

Meredith and Mantel 2012, Chapter 8

PMI®, PMBOK® Guide, 2013, 176–177

1. a. –1

   The imposed finish date becomes the late finish for Activity I. The late dates for each activity need to be recalculated. The dates for Activity E become—

Meredith and Mantel 2012, Chapter 8

PMI®, PMBOK® Guide, 2013, 176–177

1. b. 11

   The late dates for all activities need to be recalculated given the changed duration. Activity G’s revised late dates are—

   LF = 11

   LS = 6

Meredith and Mantel 2012, Chapter 8

PMI®, PMBOK® Guide, 2013, 176–177

1. b. A milestone

   A milestone is a significant point or event in the project. Milestones may be required by the project sponsor, customer, or other external factors for the completion of certain deliverables. They are similar to schedule activities, with the same structure and objectives, but they have zero duration as they represent a moment in time. [Planning]

PMI®, PMBOK® Guide, 2013, 153

1. a. Lag

   For example, in a finish-to-start dependency with a 20-day lag, the successor activity cannot start until 20 days after the predecessor has finished. [Planning]

PMI®, PMBOK® Guide, 2013, 158–159

1. c. Three-point estimates

   Three-point estimates are used to determine the estimates that go into the schedule. [Planning and Monitoring and Controlling]

PMI®, PMBOK® Guide, 2013, 170–171, 188–190

1. a. “Start no earlier than”

   Imposed dates on schedule activity starts of finishes can be used to restrict the start of finish to occur either no earlier than a specified date or no later than a specified date. Although all four date constraints typically are available in project management software, “start no earlier than” and “finish no later than” constraints are more commonly used. [Planning]

PMI®, PMBOK® Guide, 2013, 543

1. b. Schedule management plan

   The schedule management plan is part of the overall project management plan and defines, among other things, how schedule changes will be managed. Whether it is formal or informal, highly detailed or broadly framed, it generally is based on specific project needs. [Planning]

PMI®, PMBOK® Guide, 2013, 148–149

1. b. Monte Carlo analysis

   What-if scenarios (simulation) is a tool and technique for developing schedules by which multiple project durations with different sets of activity assumptions are calculated. Monte Carlo analysis is the most commonly used simulation technique. [Planning]

PMI®, PMBOK® Guide, 2013, 180

1. b. 70 weeks

$\begin{array}{l}E(t)\text{=}\frac{\text{Optimistic + (4 x Most likely) + Pessimistic}}{6}\\ \text{=}\frac{\text{40 + 200 + 180}}{\text{6}}\text{=}\frac{\text{420}}{\text{6}}\text{= 70 weeks}\end{array}$

[Planning]

PMI®, PMBOK® Guide, 2013, 170–171

1. b. Fast tracking

   Fast tracking is a way to accelerate the project schedule. [Planning]

PMI®, PMBOK® Guide, 2013, 181, 190, and 540

1. b. Calendar time between the start of A to the finish of B is 11 days

   The duration of A, which is three, is added to the duration of B, which is four, for a total of seven. The three days between the activities is lag and not duration. The lag is a constraint and must be taken into account as part of the network calculations, but it does not consume resources. The total time by the calendar is 11 days as counted from the morning of Monday the 4th. The lag occurs over Thursday, Friday, and Saturday. Sunday is a nonworkday, so activity B does not start until Monday the 11th. Therefore, the calendar time is 11 days, and activity B ends on Thursday the 14th. [Planning]

PMI®, PMBOK® Guide, 2013, 156, 158–159, and 180

1. b. Analogous estimating

   Although limitations exist with all estimating approach, analogous estimating is often used when there is a limited amount of information for the project. It uses historical information and expert judgment. [Planning]

PMI®, PMBOK® Guide, 2013, 169

1. d. Mandatory or hard

   Mandatory dependencies may be required contractually or be inherent in the nature of the project work. They describe a relationship in which the successor activity cannot be started because of physical constraints until the predecessor activity has been finished. For example, software cannot be tested until it has been developed (or coded). They should not be confused with assigning schedule constraints in the scheduling tool. [Planning]

PMI®, PMBOK® Guide, 2013, 157

1. c. Project schedule

   The approved project schedule is a key input to schedule control. It is the schedule baseline, as it is the approved version of a schedule model, and it provides the basis for measuring and reporting schedule performance. [Monitoring and Controlling]

PMI®, PMBOK® Guide, 2013, 181,187

1. d. Resource reallocation

   While resource leveling will often result in a project duration that is longer than the preliminary schedule as the original critical path probably will change and increase, it can also be used to get a schedule back on track by reassigning activities from noncritical to critical path activities. [Planning]

PMI®, PMBOK® Guide, 2013, 179

1. d. C, A, F, and G

   First, it is necessary to determine the critical path, which is A, C, F, and G. To determine the lowest weekly crashing cost, start with C at $1,500 per week. The next activity is A, followed by F and G. [Planning]

PMI®, PMBOK® Guide, 2013, 180; Kerzner 2009, 516–519

1. d. Finish-to-finish

   The completion of the work of the successor activity depends upon the completion of the work of the predecessor activity. [Planning]

PMI®, PMBOK® Guide, 2013, 156

1. c. Final output is described as schedule activities.

   In the create WBS process, final output is described as deliverables or tangible items. In the define activities process, final output is described as activities. [Planning]

PMI®, PMBOK® Guide, 2013, 151

1. b. Every activity is connected to at least one predecessor and at least one successor

   The sequence activity process involves identifying and documenting relationships among the project activities. However, the last activity or milestone are not connected to at least one successor. [Planning]

PMI®, PMBOK® Guide, 2013, 156

1. a. Project is running behind the monetary value of the work it planned to accomplish

   The SPI represents how much of the originally scheduled work has been accomplished at a given period in time, thus providing the project team with insight as to whether the project is on schedule. [Monitoring and Controlling]

PMI®, PMBOK® Guide, 2013, 189–190, 224

1. c. Several identical or nearly identical series of activities are repeated throughout the project.

   When identical network descriptions are repeated throughout a project, templates of those activities can be developed. If those series of tasks are repeated several times, the template can be updated several times. Software can be used with the templates to facilitate documenting and adapting them for future use. The sub-network or fragment tends to represent a sub-project or a work package and is often used to illustrate or study some potential or proposed schedule condition, such as a change in preferential schedule logic or the scope of the project. [Planning]

PMI®, PMBOK® Guide, 2013, 564

1. a. The cost and time slope for each critical activity that can be expedited

   Slope = (Crash cost – Normal cost)/(Crash time – Normal time). This calculation shows the cost per day of crashing the project. The slope is negative to indicate that as the time required for a project or task decreases, the cost increases. If the costs and times are the same regardless of whether they are crashed or normal, the activity cannot be expedited. [Planning]

Meredith and Mantel 2012, 390; PMI®, PMBOK® Guide, 2013, 181

1. c. Project scope baseline

   The scope baseline—made up of the scope statement, WBS, and WBS dictionary—is a key input to the define activities process and are used to develop the activity list that subsequently will help to create the schedule. [Planning]

PMI®, PMBOK® Guide, 2013, 151

1. a. Scheduled start or completion of major deliverables and key external interfaces

   Milestones are singular points in time, such as the start or completion of a significant activity or group of activities. [Planning]

PMI®, PMBOK® Guide, 2013, 182

1. a. Variance analysis

   Performance of variance analysis during the schedule monitoring process is a key element of time control. Float variance is an essential planning component for evaluating project time performance. [Monitoring and Controlling]

PMI®, PMBOK® Guide, 2013, 189

1. a. Total float for the activity is nine days.

   Total float or slack is computed by subtracting the early start date from the late start date, or 19 – 10 = 9. To compute the early finish date given a duration of 4, we would start counting the activity on the morning of the 10th; therefore, the activity would be completed at the end of day 13, not 14 (10, 11, 12, 13). If we started the activity on its late start date on the morning of the 19th, we would finish at the end of day 22, not 25. Insufficient information is provided to determine whether this activity can be completed in 2 days if the resources are doubled. [Planning]

Meredith and Mantel 2012, 352–353; PMI®, PMBOK® Guide, 2013, 177

1. a. Activity attributes

   Identifying activity attributes is helpful for further selection and sorting of planned activities. They are used for schedule development and for report formatting purposes. [Planning]

PMI®, PMBOK® Guide, 2013, 153

1. c. Schedule management plan

   While there are a number of inputs to define activities, the schedule management plan is a key input. It shows the level of detail necessary to manage the work. [Planning]

PMI®, PMBOK® Guide, 2013, 150

1. a. Review scenarios to bring the schedule in line with the plan

   A corrective action is anything that is done to bring expected future schedule performance in line with the schedule baseline. Regarding the project schedule, it usually means taking action to speed up the project. One way to determine why the schedule performance is not in line with the plan is what-if analysis, which may address schedule activities and other scenarios other than the activity that is actually causing the variance. It evaluates scenarios in order to predict their effect on the project’s outcomes, either positive or negative. [Monitoring and Controlling]

PMI®, PMBOK® Guide, 2013, 180, 186

1. b. Free float

   Free float is defined as the amount of time an activity can be delayed without delaying the early start of any immediately succeeding activities. [Planning]

PMI®, PMBOK® Guide, 2013, 177

1. b. The first step is to use conservative estimates for activity durations

   When using critical chain techniques, the initial project schedule is developed using duration estimates with required dependencies and defined constraints as inputs. [Planning]

PMI®, PMBOK® Guide, 2013, 178

1. a. Describe any unusual sequencing in the network

   A summary narrative can accompany the schedule network diagram and describe the approach used to sequence the activities in the network. This narrative also should describe any unusual sequences in the network. [Planning]

PMI®, PMBOK® Guide, 2013, 159

1. b. Sequence activities

   The risk register may require updates in both the sequence activities and develop schedule processes. In the sequence activity process, the activity lists and activity attributes may need updates as well. [Planning]

PMI®, PMBOK® Guide, 2013, 160, 185

1. b. Published estimating data

   In estimating activity resources, published estimating data is a tool and technique that is used as many companies routinely publish updated production rates and unit costs of resources. This includes labor trades, material, and equipment for different countries and geographic locations in these countries. [Planning]

PMI®, PMBOK® Guide, 2013, 164

1. b. 68.26 percent

   First, compute the standard deviation:

$\sigma =\frac{P-O}{6}\text{or}\frac{36-6}{6}=\text{5 days}$

Next, compute PERT expected time:

$\frac{P+4(ML)+O}{6}\text{or}\frac{36+4(21)+6}{6}=21\text{days}$

Finally, determine range of outcomes using 1σ:

21–5 = 16 days, and 21+5 = 26 days

Simply defined, 1σ is the amount on either side of the mean of a normal distribution that will contain approximately 68.26 percent of the population. [Planning]

Meredith and Mantel 2012, 348–350

1. c. A resource calendar

   Project and resource calendars identify periods when work is allowed. Project calendars affect all resources. Resource calendars affect a specific resource or a resource category, such as a labor contract that requires certain workers to work on certain days of the week. [Planning]

PMI®, PMBOK® Guide, 2013, 163, 184, and 558

1. d. Productivity metrics

   Duration estimates may include contingency reserves, and contingency should be identified clearly in schedule documentation. They are built into the overall project schedule to account for uncertainty. They also may be developed using quantitative analysis methods. When more information is known about the project, the contingency reserve may be used, reduced, or eliminated. [Planning]

PMI®, PMBOK® Guide, 2013, 171

1. c. Provide the ability to show performance for a specified time period for trend analysis

   Because schedule performance index (SPI) and cost performance index (CPI) are expressed as ratios, they can be used to show performance for a specific time period or trends over a long-time horizon. [Monitoring and Controlling]

Kerzner 2009, 650–652

PMI®, PMBOK® Guide, 2013, 190, 219, and 224