Exam
Name___________________________________
MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question.
1)
Managing resources should be considered:
1)
A)
during execution of a project.
B)
during all stages of a project.
C)
during initiation and planning of a project.
D)
during control and close–out stages of a project.
Answer:
B
A)
B)
C)
D)
2)
A(n) ________ is a hierarchical, graphical representation of all needed resources ordered by type or
category.
2)
A)
resource graph
B)
resource breakdown schedule
C)
activity resource requirements
D)
bill of resources
Answer:
B
A)
B)
C)
D)
3)
The process of putting procedures and rules in place for controlling changes to the project
schedules is called:
3)
A)
schedule control.
B)
schedule model.
C)
schedule procedure manual.
D)
schedule management.
Answer:
A
A)
B)
C)
D)
4)
________ is a technique used to establish contingency reserves during a project to guard against
potential risks.
4)
A)
Contingency planning
B)
Buffering
C)
Reserve analysis
D)
Contingency analysis
Answer:
C
A)
B)
C)
D)
1
5)
The time an activity can be delayed without affecting the immediately following activity is called:
5)
A)
lead time.
B)
free slack.
C)
total slack.
D)
lag time.
Answer:
B
A)
B)
C)
D)
6)
________ use a process of evaluating alternative strategies by observing how changes to selected
factors affect other factors and outcomes.
6)
A)
What–if analyses
B)
Monte Carlo analyses
C)
Monaco analyses
D)
If–then analyses
Answer:
A
A)
B)
C)
D)
7)
The estimation of activities’ durations using some type of mathematical process is called:
7)
A)
mathematical estimating.
B)
psychometric estimating.
C)
econometric estimating.
D)
parametric estimating.
Answer:
D
A)
B)
C)
D)
8)
Critical chain scheduling:
8)
A)
does not use feeding buffers.
B)
eliminates any buffers from individual activities to create a project buffer.
C)
eliminates all buffers from the project.
D)
is not concerned with resources.
Answer:
B
A)
B)
C)
D)
9)
The ________ is a dedicated part of the organization whose purpose is to focus on various aspects
of project management and provide services to the rest of the organization along those dimensions.
9)
A)
project management office
B)
project management bureau
C)
project support office
D)
project maintenance office
Answer:
A
A)
B)
C)
D)
2
10)
The actual time spent working on an activity, not accounting for any breaks, is called:
10)
A)
length.
B)
duration.
C)
effort.
D)
time.
Answer:
C
A)
B)
C)
D)
11)
All of the following are techniques for estimating activity duration EXCEPT:
11)
A)
analogous estimating.
B)
psychometric estimating.
C)
expert judgment.
D)
reserve analysis.
Answer:
B
A)
B)
C)
D)
12)
________ is an analysis used to evaluate the effects of variance on the schedule of project activities.
12)
A)
Performance measurement
B)
Variance analysis
C)
Schedule variation control
D)
Schedule variance assessment
Answer:
B
A)
B)
C)
D)
13)
The process of determining start and finish dates for project activities is called:
13)
A)
time management.
B)
start–finish analysis.
C)
schedule development.
D)
network diagramming.
Answer:
C
A)
B)
C)
D)
14)
The performance of activities in parallel that would normally be performed in sequence in an
attempt to shorten the duration of a project is called:
14)
A)
fast–tracking.
B)
PERT.
C)
schedule compression.
D)
crashing.
Answer:
A
A)
B)
C)
D)
3
15)
The shortest time in which a project can be completed is shown by the:
15)
A)
crucial path
B)
longest path.
C)
shortest path.
D)
addition of all paths.
Answer:
B
A)
B)
C)
D)
16)
What are examples of resources?
16)
A)
Money, people, and materials
B)
Technology and space
C)
All of the above
D)
None of the above
Answer:
C
A)
B)
C)
D)
17)
The estimation of activities’ durations based upon the duration of similar activities is called:
17)
A)
analogous estimating.
B)
parametric estimating.
C)
similarity estimating.
D)
psychometric estimating.
Answer:
A
A)
B)
C)
D)
18)
The practice of dedicating extra resources to a particular activity in an attempt to finish the activity
sooner than the scheduled completion date is called:
18)
A)
fast–tracking.
B)
PERT.
C)
schedule compression.
D)
crashing.
Answer:
D
A)
B)
C)
D)
19)
________ is an estimating technique in which complex activities are further decomposed to a point
where more accurate estimates can be made.
19)
A)
Expert judgment
B)
Bottom–up estimating
C)
Alternatives analysis
D)
Published estimating data
Answer:
B
A)
B)
C)
D)
4
20)
A ________ is a control system developed to outline the process for the evaluation and
implementation of schedule changes.
20)
A)
project control system
B)
schedule model control system
C)
schedule change control system
D)
scope control system
Answer:
C
A)
B)
C)
D)
21)
Resources:
21)
A)
affect both the time and the cost of a project.
B)
affect the cost of a project.
C)
do not affect a project much.
D)
affect the time to complete a project.
Answer:
A
A)
B)
C)
D)
22)
The critical path method determines the sequence of task activities that directly affect the
completion of a project by:
22)
A)
adding all activities in a network diagram.
B)
determining the shortest path through a network diagram.
C)
determining the longest path through a network diagram.
D)
subtracting the shortest path from the longest path in a network diagram.
Answer:
C
A)
B)
C)
D)
23)
The elapsed time between start and finish of an activity is referred to as:
23)
A)
length.
B)
time.
C)
duration.
D)
effort.
Answer:
C
A)
B)
C)
D)
24)
The ________ is a very detailed listing of the resource requirements for the individual activities.
24)
A)
bill of resources
B)
activity resource requirements
C)
resource breakdown schedule
D)
activity list
Answer:
B
A)
B)
C)
D)
5
25)
________ is the measure of the alternative opportunities forgone in the choice of one good or
activity over others.
25)
A)
Forgone cost
B)
Sunk cost
C)
Opportunity cost
D)
Prospect cost
Answer:
C
A)
B)
C)
D)
26)
Hard data from specific activities carried out on previous projects that may be used to more
accurately estimate resource needs is called:
26)
A)
bottom–up estimating.
B)
expert judgment.
C)
alternatives analysis.
D)
published estimating data.
Answer:
D
A)
B)
C)
D)
27)
The process used to determine the magnitude and criticality of schedule variations is called:
27)
A)
critical path model.
B)
order–of–magnitude estimation.
C)
criticality assessment.
D)
performance measurement.
Answer:
D
A)
B)
C)
D)
28)
The estimation of activities’ durations by averaging optimistic, pessimistic, and most likely
estimates is called:
28)
A)
likelihood procedure.
B)
OPL–method.
C)
three–point estimates.
D)
duration averaging.
Answer:
C
A)
B)
C)
D)
29)
________ is an estimating technique in which trade–offs between the time needed, the resources
invested, and the desired quality of the final deliverable are examined.
29)
A)
Alternatives analysis
B)
Expert judgment
C)
Published estimating data
D)
Bottom–up estimating
Answer:
A
A)
B)
C)
D)
6
30)
The estimation based on the experience of one or more experts on the particular activity or project
is called:
30)
A)
published estimating data.
B)
expert judgment.
C)
alternatives analysis.
D)
bottom–up estimating.
Answer:
B
A)
B)
C)
D)
31)
The longest path through a network diagram, considering both task dependencies and resource
dependencies is called:
31)
A)
resource path.
B)
critical chain.
C)
critical path.
D)
resource chain,
Answer:
B
A)
B)
C)
D)
32)
The process of calculating expected, early, and late start and finish dates of a project is called:
32)
A)
reserve analysis.
B)
schedule network analysis.
C)
EEL analysis.
D)
PERT analysis.
Answer:
B
A)
B)
C)
D)
33)
Under conditions of unlimited resources the critical path:
33)
A)
is not affected by the critical chain.
B)
is shorter than the critical chain.
C)
is longer than the critical chain.
D)
and the critical chain are equal.
Answer:
D
A)
B)
C)
D)
34)
In information systems development projects, ________ would be (an) example(s) of capital
resources.
34)
A)
the project manager
B)
the development platform
C)
the technological platform the software resides on
D)
both the development platform and the technical platform the software resides on
Answer:
D
A)
B)
C)
D)
7
35)
The sequence of activities:
35)
A)
can only be determine when considering resources.
B)
can be determined without considering resources.
C)
cannot be determined without considering resources.
D)
none of the above.
Answer:
B
A)
B)
C)
D)
36)
Any activity on the critical path:
36)
A)
is called critical activity.
B)
contains free slack.
C)
contains total slack.
D)
is represented in blue in Microsoft Project.
Answer:
A
A)
B)
C)
D)
37)
The time an activity can be delayed without affecting the overall completion date of a project is
called:
37)
A)
lag time.
B)
free slack.
C)
lead time.
D)
total slack.
Answer:
D
A)
B)
C)
D)
38)
Inputs into the activity resource estimating process include:
38)
A)
outputs from prior stages of the project.
B)
process assets.
C)
enterprise environmental factors.
D)
all of the above.
Answer:
D
A)
B)
C)
D)
39)
________ is any form of network analysis where resource management issues drive scheduling
decisions.
39)
A)
Schedule leveling
B)
Resource analysis
C)
Resource management
D)
Resource leveling
Answer:
D
A)
B)
C)
D)
8
40)
Crashing and fast–tracking are ________ techniques.
40)
A)
schedule shortening
B)
path adjustment
C)
schedule adjustment
D)
schedule compression
Answer:
D
A)
B)
C)
D)
41)
Human resources include:
41)
A)
support staff.
B)
end users.
C)
customers.
D)
all of the above.
Answer:
D
A)
B)
C)
D)
42)
All of the following are tools and techniques to estimate resources EXCEPT:
42)
A)
alternative analysis.
B)
bottom–up estimating.
C)
activity–resource analysis.
D)
expert judgment.
Answer:
C
A)
B)
C)
D)
43)
The longest path through a network diagram is the:
43)
A)
critical path.
B)
longest path.
C)
network path.
D)
critical chain.
Answer:
A
A)
B)
C)
D)
44)
________ is a technique that is used to estimate project duration when individual activity duration
estimates are uncertain.
44)
A)
PERT
B)
OPR–method
C)
Three–point estimate
D)
Likelihood procedure
Answer:
A
A)
B)
C)
D)
9
45)
________ is the process of estimating the duration of the project activities using both project scope
and resource information.
45)
A)
Resource estimation
B)
Scope duration estimation
C)
Activity duration estimation
D)
Project duration estimation
Answer:
C
A)
B)
C)
D)
46)
Resource allocation:
46)
A)
is mostly an easy task.
B)
is overrated.
C)
plays a large role in determining activity duration.
D)
does not affect activity duration.
Answer:
C
A)
B)
C)
D)
47)
________ are probabilistic analyses used to calculate the distribution of results.
47)
A)
Bellagio simulations
B)
Monaco simulations
C)
Vegas simulations
D)
Monte Carlo simulations
Answer:
D
A)
B)
C)
D)
48)
The critical path in a network diagram illustrates the:
48)
A)
shortest time in which a project can be completed.
B)
longest time in which a project is completed.
C)
effect of accumulated slack.
D)
importance of resource leveling.
Answer:
A
A)
B)
C)
D)
49)
Dates imposed to meet some type of development deadline are called:
49)
A)
imposed dates.
B)
external dependencies.
C)
mandatory dates.
D)
none of the above.
Answer:
A
A)
B)
C)
D)
10
50)
Resource leveling heuristics are ________ used to allocate resources to project activities.
50)
A)
preferences
B)
hard–and–fast rules
C)
rules of thumb
D)
policies
Answer:
C
A)
B)
C)
D)
51)
The use of mathematical techniques to shorten a project’s duration is called:
51)
A)
schedule compression.
B)
crashing.
C)
PERT.
D)
fast–tracking.
Answer:
A
A)
B)
C)
D)
52)
A ________ contains data and information that are compiled and used in conjunction with manual
methods or project management software to perform schedule network analysis and to generate
the schedule.
52)
A)
schedule repository
B)
project management plan
C)
project workbook
D)
schedule model
Answer:
D
A)
B)
C)
D)
SHORT ANSWER. Write the word or phrase that best completes each statement or answers the question.
53)
The selection of personnel may be influenced by the availability, costs, and ________ of the
resource pool the project manager has access to.
53)
Answer:
skills
54)
Critical chain scheduling uses a ________ to protect the final due date of a project.
54)
Answer:
project buffer
55)
Using critical chain scheduling, a ________ is added to any noncritical activity feeding into
a critical activity.
55)
Answer:
feeding buffer
56)
A ________ displays the availability of the different resources.
56)
Answer:
resource calendar
11
57)
PERT analysis is a special form of ________.
57)
Answer:
three–point estimate
58)
________ is an analysis to evaluate the effects of variance on the schedule of project
activities.
58)
Answer:
Variance analysis
59)
The ________ determines the process for evaluating and implementing potential schedule
changes.
59)
Answer:
schedule change control system
60)
For almost any activity, there is a tradeoff between the time needed, the resources invested,
and the ________ of the final deliverable.
60)
Answer:
quality
61)
________ is performing activities in parallel that would normally be performed in sequence
to shorten the duration of a project.
61)
Answer:
Fast–tracking
62)
The sequence of activities can be determined ________ the resources.
62)
Answer:
without considering
63)
An example of parametric estimating is the number of ________.
63)
Answer:
lines of code
64)
A fundamental part of scheduling a project is to determine the tasks’ durations, which
involves ________ that need to be assigned to the tasks.
64)
Answer:
assessing the resources
65)
The longest path through a network diagram illustrates the ________ in which a project can
be completed.
65)
Answer:
shortest time
66)
In information systems development projects, both the ________ and the technological
platform that the software resides on would be examples of capital resources.
66)
Answer:
development environment
12
67)
The ________ aids project managers in determining when activities can be performed
given resources and constraints.
67)
Answer:
schedule network analysis
68)
In contrast to the critical path method, which assigns a determinist start and finish date for
each activity, PERT uses a ________.
68)
Answer:
weighted average method
69)
Free slack is also known as ________.
69)
Answer:
free float
70)
________ is a process used to determine the magnitude and criticality of schedule
variations.
70)
Answer:
Performance measurement
71)
Capital resources are the tools and ________ used to produce other goods and services.
71)
Answer:
infrastructure
72)
Resources are sources of supply and support, and include money, people, materials
technology, and ________.
72)
Answer:
space
73)
________ is the elapsed time between the start and the finish of an activity.
73)
Answer:
Duration
74)
The critical chain method is used when activities contend for ________.
74)
Answer:
limited resources
75)
Analogous estimating is well suited for ________ tasks.
75)
Answer:
standard
76)
Activity duration estimation becomes ________ as the project progresses.
76)
Answer:
more precise
77)
________ is an attempt to finish an activity sooner than the scheduled completion date by
dedicating extra resources to it.
77)
Answer:
Crashing
13
78)
________ slack is the time an activity can be delayed without affecting the immediately
following activity.
78)
Answer:
Free
79)
________ is the measure of the alternative opportunities forgone in the choice of one good
or activity over others.
79)
Answer:
Opportunity cost
80)
________ slack is the time and activity can be delayed without affecting the overall
completion date of a project.
80)
Answer:
Total
81)
A ________ is a hierarchical graphical representation of all needed resources ordered by
category.
81)
Answer:
resource breakdown structure
82)
________ are dates that are imposed to meet some form of development deadline.
82)
Answer:
Imposed dates
83)
________ is the process of determining start and finish dates for project activities.
83)
Answer:
Schedule development
84)
________ are probabilistic analyses used to calculate a distribution of likely results.
84)
Answer:
Monte Carlo simulations
85)
The prudent project manager should provide ________ rather than point estimates.
85)
Answer:
range
86)
The activity resource requirements should include any ________ made during the
estimation process.
86)
Answer:
assumptions
87)
Human resources include all project ________, including customers, project team
members, support staff, project suppliers, and end users.
87)
Answer:
stakeholders
88)
Total slack is also known as ________.
88)
Answer:
total float
14
89)
An activity on the critical path is referred to as a ________.
89)
Answer:
critical activity
90)
Published estimating data is a form of ________.
90)
Answer:
benchmarking
91)
Reserve analysis is a technique used to establish contingency reserves during a project to
________.
91)
Answer:
guard against potential risk
92)
The critical path is the ________ through a network diagram.
92)
Answer:
longest path
93)
If resources were unlimited, the critical path and the critical chain were ________.
93)
Answer:
equal
94)
The ________ can give very precise estimates about the resources needed.
94)
Answer:
“doers”
95)
The resources used to complete tasks may also influence the ________ of project
deliverables.
95)
Answer:
quality
96)
In terms of project time management, resource allocation plays a large role in determining
________.
96)
Answer:
activity duration
97)
________ is the actual time spent working on an activity.
97)
Answer:
Effort
TRUE/FALSE. Write ‘T’ if the statement is true and ‘F’ if the statement is false.
98)
For almost any activity, there is a tradeoff between the time needed, the resources invested, and the
desired quality of the final deliverable.
98)
Answer:
True
False
99)
The critical path is the shortest path through a network diagram and shows the shortest time in
which a project can be completed.
99)
Answer:
True
False
15
100)
For information systems projects, analogous estimating can be used for standard tasks such as
building interfaces.
100)
Answer:
True
False
101)
In terms of project time management, resource allocation does not affect activity duration.
101)
Answer:
True
False
102)
For experienced project managers, it is okay to give quick resource estimates based on gut feelings.
102)
Answer:
True
False
103)
The critical chain method adds project buffers to noncritical activities feeding into critical activities.
103)
Answer:
True
False
104)
The combination of resource needs and resource availability helps to determine the time needed to
complete the individual activities as well as the entire project.
104)
Answer:
True
False
105)
The sequence of activities cannot be determined without considering the resources.
105)
Answer:
True
False
106)
Under unlimited resources, the critical chain is shorter than the critical path.
106)
Answer:
True
False
107)
When managers choose one resource over others, an opportunity cost for the organization
sometimes results.
107)
Answer:
True
False
108)
A Monte Carlo simulation is used for evaluating alternative strategies by observing how changes to
selected factors affect other factors and outcomes.
108)
Answer:
True
False
109)
Crashing refers to dedicating extra resources to a particular activity in an attempt to finish the
activity sooner than the scheduled completion date.
109)
Answer:
True
False
110)
Duration is the actual time spent working on an activity.
110)
Answer:
True
False
16
111)
Human resources include all project stakeholders.
111)
Answer:
True
False
112)
For most project planning activities, it is possible to give precise duration estimates early on.
112)
Answer:
True
False
113)
The number of lines of code is an example of parametric estimating for duration estimating.
113)
Answer:
True
False
114)
In critical chain scheduling, a project buffer is used to protect the final due date of a project.
114)
Answer:
True
False
115)
Assigning more resources can always speed up the completion of activities.
115)
Answer:
True
False
116)
Total slack is the time an activity can be delayed without affecting the immediately following
activity.
116)
Answer:
True
False
117)
In information systems projects, only the development platform would be an example of a capital
resource.
117)
Answer:
True
False
17
ESSAY. Write your answer in the space provided or on a separate sheet of paper.
118)
List and describe the five techniques for duration estimating.
Answer:
Expert judgment, previously mentioned in the activity definition process, can be used as a means to
better estimate activities’ durations and their need for specific resources. As with the use of expert
judgment during activity definition, care should be taken, for it can rely on the subjective opinion of
project participants. While programmers might be able to give a fairly accurate estimate of how long it
takes to write a certain number of lines of code, they might not be able to give accurate estimates of less
common tasks.
Analogous estimating is simply using the duration of a similar activity as a basis for estimating the
current activity. For information systems development projects, analogous estimating can be used for
standard tasks such as building interfaces. Here, historical data or expert judgment can be used to
estimate the duration of these activities, as components like these are often fairly standardized and thus
take the same amounts of time to complete. In addition to company historical data, published data (from
past projects done in the company) about durations of similar activities can be used.
Parametric estimating is a quantitatively based duration estimation technique that uses some type of
mathematical process to determine the activity’s duration. In some cases, the number of lines of code a
programmer generates in a normal workday can be used in conjunction with the number of lines of code
estimated for a given activity to determine that activity’s duration.
Three–point estimates can increase accuracy by accounting for optimistic, pessimistic, and “most likely”
estimates. To arrive at an accurate estimate, these three estimates are averaged, taking into consideration
the risk involved in completing the activities. If a high risk is associated with the activity, the estimate
will lean toward the pessimistic end. PERT analysis is a specific form of three–point estimate, where
specific weighting is applied to the optimistic, pessimistic, and “most likely” estimates. This is explained
in more detail in our discussion of PERT analyses in the schedule development section below.
Reserve analysis analyzes the different activities to establish reserve times (basically, time set aside as a
reserve in case activity durations don’t match the plan) within a project schedule for the purpose of
guarding against potential risks to the schedule. In the case of reserve time, any buffer in the project
schedule should be documented and accounted for as part of the project schedule.
119)
List and describe the resource estimation techniques presented in the PMBOK. Also, describe how
benchmarking, mind mapping, and brainstorming are used in activity resource estimation. Give examples for
each technique.
Answer:
One of the primary sources of project resource estimating is expert judgment. Usually, experts can give
valuable inputs into estimating resource needs. In most cases, the “doers” can give very precise estimates
about the resources needed. In an information systems project, the database administrator can give good
estimates about how long it takes to create certain database queries, whereas a programmer can give
good estimates about how long it takes to code common modules. However, the estimates should not be
based solely on a person’s recollection of prior projects or activities, because this will most likely lead to
biased estimates, as people often have a hard time remembering exact details. Rather, a combination of
expert judgment and hard data (e.g., data recorded from prior projects) is preferable.
Another source of hard data about resource needs is published estimating data available from market
research companies, a form of benchmarking. These companies gather and analyze research needs for a
variety of projects in a variety of industries. When planning to implement a new ERP system, for
example, you can obtain benchmarking data both from ERP vendors and from independent
organizations to help prepare estimates of resources needed. Usually, these data are based on a number of
different companies, so you can get a good overview of average, minimum, or maximum resource needs.
These data also help to benchmark one‘s resource needs against those of direct competitors or industry
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leaders.
When estimating activity resources, it is often advisable to conduct some form of alternatives analysis. For
almost any activity, there is a trade–off between the time needed, the resources invested, and the desired
quality of the final deliverable. For example, assigning more human resources to a project might speed
up the completion time, but at tremendously higher costs; further, the quality might be inconsistent
across the people working on the activity. On the other hand, fewer people might still be able to complete
the activity within the desired time frame but might introduce more errors because of time pressure.
Other times, a project manager might realize that outsourcing the activity might be the most efficient
way. Carefully analyzing these alternatives helps to make an optimal choice, given the available
resources and desired outcomes.
Bottom–up estimating is a technique applied when the resource needs of an activity cannot be estimated
very well. This is often the case if the work package itself is still fairly complex. In this case, the activity
should be decomposed further, until a level is reached where reasonable estimates can be provided. If a
work package for an ERP system consists of, say, the user interface for the payroll module, it might be
hard to estimate the resources needed to complete this deliverable; in this case, the deliverable can be
further decomposed into the individual screens, for which it is easier to estimate the resources needed.
These lower–level estimates can then be combined into an estimate for the activity itself.
In addition to the techniques listed in the PMBOK, companies use a variety of techniques to arrive at their
estimations. Benchmarking against competitors is a common practicefor example competing auto
makers might benchmark their time from conception to market. Techniques utilizing project team
members, such as brainstorming sessions or mind mapping, may also be useful in gathering valuable
information about expected project duration. In brainstorming sessions, participants are charged with
generating ideas without fear of group censure. A brainstorming session on estimating a project’s
duration, or possible problems that might be encountered, can serve as valuable input in the final
estimation. In mind mapping, visual representation of tasks and problems may help the project team
come up with more accurate project representations, and associated durations.
120)
Describe critical chain scheduling. Make sure to discuss the use of buffers in the critical chain method.
Answer:
The critical chain method is used if activities contend for limited resources. When using the critical chain
method, the critical path is first identified, independent of resource availability. Entering resource
availability might then reveal conflicting activities, which were planned to be completed in parallel but
draw upon the same (limited) resource. Based on resource availability, a new (altered) critical path is
created. This new path, based on both task dependencies and resource dependencies, is referred to as a
critical chain. If resources were unlimited, the critical path and the critical chain would be equal. So far,
this process to some extent resembles resource leveling techniques. However, another advantage of the
critical chain method is that it helps to minimize uncertainty in a project’s schedule, therefore leading to a
shorter overall completion time. The following paragraphs explain how critical chain scheduling can be
used to influence a project’s completion date.
People assigned to multiple concurring tasks often resort to multitasking, that is, working a bit on one
task, going on to the next, working a bit on a third task, and so on, before restarting work on task one.
Unfortunately, this approach often wastes time because of setup for the individual tasks. Therefore,
critical chain scheduling prohibits multitasking with the goal of arriving at a shorter overall completion
time. Another factor often leading to long project durations is the uncertainty inherent in any project. To
cope with this uncertainty, a project’s activities often contain duration buffers (i.e., additional time
allocated to an activity to account for any unforeseen circumstances). As this buffer is added to every
activity, the entire project contains more reserve time than is usually needed. Further, there is often the
tendency to fill the allotted time; in other words, if a certain amount of time is allotted for an activity,
people tend to use it (also known as “Parkinson’s Law”). If a buffer is added to an activity, people tend to
use this buffer as well, no matter whether the additional time is needed or not. CCM thus suggests
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following aggressive target duration schedules to reduce over–allocation of time, placing buffers at more
strategic locations in the project timeline, avoiding multitasking because there are switching costs,
emphasizing resources and the contention for resources when planning, and finally tracking the status of
buffers managing both their depletion and replenishment.
Critical chain scheduling eliminates any buffers from the individual activities; instead, a general project
buffer is created. Eliminating individual buffers helps to decrease the entire duration of the project, while
the project buffer protects the final due date. The removal of individual buffers serves the additional
purpose of discouraging people from engaging in multitasking or other distractions. As the duration
estimates (without the individual buffers) are very aggressive, people focus on the task at hand in order to
finish the task in the allotted time.
In addition to the project buffer, critical chain scheduling uses feeding buffers to protect the activities on
the critical path. Usually, in complex projects, many noncritical activities feed into critical activities. As
the individual safety buffers are eliminated using critical chain scheduling, a change in duration of a
noncritical activity feeding into a critical activity would influence the critical path and, thus, the duration
of the entire project. To prevent this, a feeding buffer is added to any noncritical activity feeding into a
critical activity. The project manager can easily monitor the use of the feeding buffers and the project
buffer to determine whether the project is on schedule. Project management software frequently employs
third-party add-ons for critical chain scheduling.
When using any of these techniques, a project manager should always monitor the project calendars and
resource calendars. In a large software development project of a multinational corporation, virtual teams
located in different regions of the world might be working on completing a certain task; thus, teams
could work in three continuous shifts. The resource calendar would specify these working times. On the
other hand, the client organization might be available only during certain times, so that, for example,
during requirements generation, the project team members cannot get in contact with it. Such times
would be specified in the project calendar.
Another factor to be considered during schedule network analysis is the use of leads and lags. In the
activity sequencing stage, the leads and lags of the different activities have been established. To review, a
lead is the time between the start of one activity and the start of an overlapping activity; a lag is the time
between the finish of one activity and the start of a succeeding activity. As these leads and lags can
significantly influence the schedule, their use should be carefully double-checked to minimize potentially
negative impacts on the schedule.
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