1. Lab Exercise 6.01: Defining the Project Activities
It’s essential for a project manager and the project team to accurately identify the project
activities. You don’t want to get too far along in the project execution and realize that you forgot
to include, estimate, and plan for project activities. Imagine the cost and time overruns, not to
mention stakeholder frustrations, if you forget to include the cost and time estimates for activities
in your project.
In order to find the project activities, you’ll first need your project’s scope baseline. Recall that
the scope baseline is the collection of the project scope statement, the WBS, and the WBS
Dictionary. These three documents will help you determine what activities are needed to create
the elements of the project scope. Chief among these, as you can imagine, is the project’s WBS.
You’ll need to identify the activities that your project team will need to do in order to create the
work packages of the WBS. The actual creation of the activity list is similar to the creation of the
WBS, and it’s also called decomposition. The idea is that you’re decomposing the work
packages of the WBS to the activity list of your project.
PMP For many projects, you can define the project activities right along with your
Coach creation of the WBS. There’s no real reason to fully decompose the WBS and
ignore the activity list until the WBS is created. You can create, in many projects,
the WBS and the corresponding activity list in unison.
If an organization is completing the same types of projects, the project manager can, and should,
rely on organizational process assets to help identify the project’s activity list. Basically the
project manager will take a similar project and adapt the activity list from the previous project to
the current project. The project manager should make certain that the activity list that is being
adapted to the current project, however, is accurate. It won’t do the project good to adapt a faulty
activity list from a previous project.
The project manager is basically using an activity list template when she adapts a previous
project to a current project. It’s also common that some standard, prepopulated activities could
exist within a project’s activity list template. Consider all of the project management activities
that a project manager is required to do in an organization. These standard activities could be
part of an activity list template so that none of these important activities are forgotten by the
project manager or project team.
Your organization may also use enterprise environmental factors as an input to the activity list
creation. The enterprise environmental factors are the rules that you’re required to follow in your
organization and industry. For example, an organization can require that the project manager
document the activity list using certain project management software and have the activity list
2. approved by the project sponsor. Some disciplines may require certain activities, such as
inspections, audits, or reviews, as part of the project work.
The best and most often used tool in creating the activity list is simply expert judgment. Expert
judgment requires the project manager, the project team, and other experts familiar with the
project work to examine the project requirements, the WBS, and the work packages to make
certain all of the needed project activities are identified in the activities list. Expert judgment
could mean consultants, other project managers, and other resources within the organization
familiar with the work the project is to complete.
As you create the project’s activity list, you should also include activity attributes. These
attributes will evolve over time as more information becomes available in the project. Activity
attributes can include
A description of the activity
Unique activity identification
Associated WBS work package identification
Predecessor and successor activities
Any lead or lag information
Resource requirements
Imposed dates
Constraints and assumptions
Any other relevant information about the work packages
The activity list can help the project team and stakeholders identify the milestone list in the
project. A milestone is a significant checkpoint in the project and shows progress toward the
project’s completion date. The project manager can see all of the required activities in the project
that lead up to and create each project milestone. The milestone list is created and updated
throughout project planning and is part of the overall project schedule.
Learning Objectives
In this lab you’ll experiment with creating an activity list. You’ll examine an existing WBS and
then create a sample activity list to experience the process of WBS decomposition to the project
activities. By the end of this lab you’ll be able to
Identify the work packages of the WBS
Decompose work packages into activities
Organize the activity list by WBS components
Explain the process of creating a project’s activity list
Create an Activity List
You are the project manager of the HYU Project. This project’s mission is to educate
your company’s employees about new software that will be implemented in the
organization. The new software, called FACE, addresses the needs of the
3. organization’s facility management. As your company has grown, competition for
meeting rooms, equipment, and other facilities has become more cumbersome to
manage. The FACE software will address these concerns and will help employees
submit, track, and organize requests for meeting rooms, facilities, and equipment that
your company uses. Your project is to train and create a level of support for FACE.
You, your project team, and several key stakeholders have worked together to create
the WBS for the FACE Project. Now you will lead the project team in the process of
identifying the needed activities for each work package.
In the following table you’ll take each identified work package and define the needed
activities to create the project deliverable. You don’t need to be familiar with training,
development, or software creation to complete this exercise. The point of the exercise
is to experience the concept of creating an initial activity list for a project based on the
WBS. If you’re not certain what type of activities should come from the WBS
component, you can search the Internet or just create sample activities for this
exercise.
WBS Component Associated Activities
457.1 FACE Training
457.1.1 Course Objectives
457.1.2 Course Exercises
457.1.3 FACE Course Book
457.1.4 FACE User Guide
457.2 Web Training
457.2.1 Web Site Structure
457.2.2 FACE Online Exercises
457.2.3 FACE Security
457.2.4 FACE FAQs
457.3 Help System
457.3.1 Structure
457.3.2 Software
457.3.3 Web Training
457.4 Guide Cards
457.4.1 Topics
457.4.2 FACE Writing
457.4.3 FACE Design
457.4.3 FACE Printed Cards
4. Lab Exercise 6.02: Sequencing the Project Activities
Once you’ve identified the project activities, you need to put them into the order in which they
should be completed. You’ll rely on your activity list, your activity attributes, the milestone list,
your project scope statement, and any organizational process assets that are relevant. The goal in
this process is to not worry about task duration, but rather to identify the most logical order in
which the activities should happen. Over time, as your project moves forward, you’ll be able to
come back to these events and change the order for the best execution in the project.
The most common approach to activity sequencing is the simple precedence diagramming
method (PDM). This approach means that your activities have predecessors and successors. For
example, you need to remove the wallpaper, prime the wall, and then paint the wall. The
“remove the wallpaper” activity is predecessor to the “prime the wall” activity. The “prime the
wall” activity is a successor and it’s a predecessor to the “paint the wall” activity. With PDM
you’ll plot out the order of the events in a workflow as in Figure 6-1. Notice in Figure 6-1 that
Activity B is a successor to Activity A and that Activity B actually has two successors—Activity
C and Activity D.
On the Job Your workplace may also call the end result of the PDM a project network
diagram. That’s fine; it’s a network of all the activities to be completed in the
project.
The relationship between activities is also determined as part of the PDM. There are four
relationship types you can use between activities in a project network diagram:
Finish-to-Start Activity A must finish so that Activity B can start. For example, you
must finish writing the text for a brochure so that the graphic designer can design the
brochure. This is the most common relationship type.
Figure 6-1: PDM uses predecessors and successors to visualize the flow of the project
work.
5. Start-to-Start Activity A must start so that Activity B can start. This is ideal for two
activities that can be executed in unison in your project and basically start at nearly the
same time. For example, you must start the creation of the web site so that the
photographer can take the photos you’ll use on the web site. These two events are
relevant to one another, but each can take place at the same time.
Finish-to-Finish Activity A must finish so that Activity B can finish. This is ideal for
activities that should be completed close together in the project timeline. For example,
the participants are completing a software training class and the IT department is
installing the new software on the participants’ computers. By the time the training is
completed, so too is the installation of the software.
Start-to-Finish Activity A must start so that Activity B can finish. This is the most
unusual scheduling relationship. It’s used in just-in-time scheduling, inventory
management, and even chemical engineering. For example, you have to start a chemical
reaction in a certain order so that the end result of the chemical reaction will finish in the
desired order. You won’t use this scheduling approach very often.
As you and your project team plot the order of events in the PDM, you’ll also determine the
dependency of the activities. Dependency determination just means that you’ll identify the order
in which the events must take place. There are three types of dependencies with the PDM
approach:
Mandatory dependencies The project work must take place in a specific order, also
known as hard logic. For example, you must first create the foundation before you can
begin framing the home.
Discretionary dependencies The project work can take place in several different
sequences based on the project manager’s discretion. For example, you might normally
paint the walls first and then install the carpet, but you could install the carpet first and
then paint the walls if you needed to. Discretionary dependencies are also known as soft
logic.
External dependencies The project work can’t take place until an external event
happens. For example, the building inspector must inspect the work, the vendor must
deliver the materials, or the weather must change before the project work may continue.
External dependencies are things that are needed in the project, but they’re basically
outside of the project manager’s control.
On top of the relationships between project activities and the dependencies in the project work,
you must also consider leads and lags for the individual project activities. Lead time is
considered negative time, as you’re bringing project activities closer to the start time and it
allows activities to overlap. For example, you’re redecorating a huge ballroom in a hotel and
your crew is priming and then painting the ballroom. Because the ballroom is so huge, there’s no
reason to wait until the entire room is primed before your painting crew can begin their work.
You can assign lead time to the painting activity to allow the priming activity and the painting
activity to overlap.
Lag time, as you may have guessed, is waiting time and is positive time. Consider a construction
project where the cement must completely dry before any framing can happen on the cement slab
6. foundation. Lag time would be “waiting time” for the cement to dry before the next activity
could actually start. Lag time causes the project duration to increase, as you’re adding time, but
not necessarily additional resources, to the project work.
Finally, if your organization is completing the same type of projects over and over, there’s little
reason to build a project network diagram from scratch. More likely you’ll just base your current
project on a similar project—much like you did for the project management plan, the WBS, and
the activity list. In this instance the template is called a schedule network template. Your network
template could be the entire project, a chunk of the project work, or you may use a subnetwork or
fragment network. A subnetwork or fragment network is a portion of your project template that
represent common work in your project. For example, you may have repetitive tasks in your
project; rather than repeating the work over and over in your network diagram, you’ll use a
subnetwork to represent this repetitive work.
Learning Objectives
In this lab you’ll explore the techniques of scheduling project activities. By the end of this lab
you’ll be able to
Draw a basic project network diagram
Define the relationships among project activities
Identify activity dependencies for a project
Explore Project Scheduling
You are the project manager of the HNH Project for your company. This project is to create a
jazz fundraiser for a local charity that will happen 60 days from today. You and your project
team have created the following activity list (presented in no particular order):
Identify jazz artists
Select a menu
Select a caterer for the event
Publicize the event
Create flyers and brochures
Create an online web site for the event
Provide videos of jazz artists for the web site
Meet with local media for publicity
Create press releases for the event
Create a ticketing software for the event through the web site
Decorate the ballroom with a music theme
Select a venue for the event
Meet with attorneys for contractual obligations to performers
Determine insurance needs for the venue
Hire wait staff for the event
Identify volunteers to help with the actual event
Hire a photographer for the event
7. Host the actual event
Make photos of the event accessible through the event web site
This lab asked you several questions about the activity list and the sequencing of the project
activities. Here are the most likely answers for this lab:
1. What are the first three activities for this event?
2. There are 19 activities in this activity list. Identify a possible sequence of activities:
3. Considering these events, create a project network diagram to show the order in which
you believe the activities should happen. Consider the multiple paths to project
completion, the relationships between project activities, and hard logic and soft logic.
Identify each task in the preceding list with an alphabetical letter and then create the
network diagram accordingly.
Lab Exercise 6.03: Estimating Activity Resources
Another process the project manager and project team will need to complete is creating an
estimate for the type and amount of resources needed by the activities in the activity list.
Resources include people, materials, equipment, and facilities that the project requires in order to
complete the activities. You’ll need to know what types of resources are necessary, especially
people, to predict how long the project work will take to complete.
PMP The process of estimating activity resources works with the estimate costs process
Coach you’ll see in the next chapter. The resources your project needs must have a cost
associated with them.
The project manager will rely on the activity list and activity attributes to begin the process of
estimating activity resources. She’ll also use the resource calendars to determine when resources
are available, as availability may affect which resource will be selected, when the project work
will take place, and negotiations internal to the organization to get needed resources onto the
project work. The project manager will also leverage any organizational process assets and
follow the rules and policies as defined in enterprise environmental factors.
One approach for determining the activity resources is to rely on published estimating data.
These are white papers, catalogs, or industry reports that help an organization to predict costs,
duration of use, and expected outcomes of work based on project work. For example, a report
could predict how long it would take to create 15,000 plastic bottles based on the type of
8. manufacturing equipment, type and thickness of plastic, and standard characteristics of the water
bottle. Published estimating data is ideal in construction and manufacturing.
Another approach that’s useful is called bottom-up estimating. Bottom-up estimating breaks
down an activity into finer details to account for all of the likely materials, type of labor, and
total quantity of labor that is needed to complete a single activity. Bottom-up estimating
examines all aspects of the activity, including dependencies, attributes, experience, and other
characteristics.
Of course the project manager is going to also use expert judgment and alternative identification
to predict activity resources. Expert judgment can be based on past projects, experience with the
project work, consultants, the project team, or other experts within the organization. Alternative
identification is also used as part of trade-offs in determining needed resources. Consider a
senior engineer versus a junior engineer to complete a given activity; the senior engineer may be
able to complete the work faster, but the junior engineer costs less.
This process documents the activity resource requirements for each activity. Project managers
often create a resource breakdown structure, similar to the WBS concept, which visualizes the
resources needed in the project. The resource breakdown structure could categorize resources by
materials, contractors, employees, or any other categorization of needed project resources.
Learning Objectives
In this lab you’ll explore estimating activity resources in a sample project scenario. By the end of
this lab you’ll be able to
Rely on expert judgment
Use alternative identification for resource identification
Research published estimating data
Explain bottom-up estimating for estimating activity resources
Estimate Activity Resources for a Project
You are the project manager for a construction company. Your company has assigned you to a
project that will create a theater for an existing condominium association. The theater in the
condo building will have state-of-the art projection, movie screen, seating for up to 50 people,
and will be decorated in a Hollywood motif. Sharon, your project sponsor, needs you to identify
some of the needed resources for the construction of the theater.
This lab asked you to answer questions regarding activity resources. Your answers may be
slightly different than what is presented here:
1. Sharon wants you to identify three different types of flooring that would be ideal for a
home theater. Using alternative identification, what are three possible resources you
could use for flooring in a home theater? You may search the Internet if needed.
9. 2. Sharon has also asked that you identify the amount of paint you’ll need to paint the
theater. The theater is 60 feet long, 40 feet wide, and 19 feet six inches high, and it has
six-inch baseboards throughout the room. There is only one door that is seven feet
high by four feet wide and has three inches of trim all around the door. You’ll need to
apply two coats of paint on standard drywall, and the paint will cover 300 square feet
per gallon. You can find calculators to help answer this information by performing an
Internet search:
3. What project management tool and technique are you using to answer question
number two in this exercise?
4. What resources can you readily identify that you’ll need in this project based on the
limited amount of information you have so far?
Lab Exercise 6.04: Estimating Activity Durations
Once you’ve identified the activities and the types of resources you’ll need and the availability of
those resources, you can create activity duration estimates. Early in the project you might create
a rough order of magnitude time estimate, or a high-level schedule for the project work, but now
that the activity list has been created, you can offer a more detailed estimate of the activity
duration and, in turn, the duration of the project. You’ll also rely on the organizational process
assets, such as historical information for creating duration estimates. Project managers also must
consider enterprise environmental factors, such as rules for the amount of time a resource is
allowed to work on a project versus regular operations.
PMP Keep in mind for your PMP exam all of the application areas that all of the
Coach different project managers specialize in. You don’t need to know how to estimate
activity duration for construction, IT, healthcare, manufacturing, and other
project types you can imagine. You will need, however, to recognize the tools and
techniques and their characteristics for estimating project activity durations.
Activities within a project are either effort-driven activities or fixed-effort activities. Effort-
driven activities are tasks to which a project manager can add more effort to reduce the overall
duration of the project work. Consider wiring a building with new network cable with two
electricians versus six electricians. By adding the extra labor, the project work can, in theory,
complete faster. The Law of Diminishing Returns restricts the project manager from
exponentially adding labor to the task to continually reduce the overall duration of the project
work. At some point the added labor is just too expensive and the workers are going to get in
each other’s way and be counterproductive.
10. Fixed-effort activities are tasks that must be completed, and adding more labor to the task won’t
shorten its duration. For example, you can’t add more labor to a printing press to make it go
faster. The printing press can only create so many units an hour, and more pressmen won’t speed
up the operation. Consider fixed-effort activities like testing software, manufacturing, or training.
One of the most common tools a project manager can use to predict activity durations is
analogous estimating. This approach, sometimes called top-down estimating, creates an analogy
between projects to predict activity duration. Analogous estimating requires historical
information, as you’re basing your current project duration estimate on a completed similar
project. While this approach is fast to use, it’s not always the most reliable duration estimating
technique.
Another approach you can use is parametric estimating. Parametric estimating relies on
parameters, such as one hour or labor per square foot of construction, to predict duration. It’s
ideal to use when a project has repetitive tasks to complete, such as installing fixtures, loading
software on many computers, or painting identical rooms. Parametric estimates can be highly
reliable, especially if the supporting detail for the estimate is based on historical information or
proven experience.
Some project managers use a three-point estimate to consider a wider range of risk tolerance. A
three-point estimate requires that for each activity optimistic, most-likely, and pessimistic
duration estimates be created. Once all three estimates are created, an average time estimate is
found. For example, an activity with an optimistic duration of 25 hours, a most-likely estimate of
35 hours, and a pessimistic estimate of 75 hours would have a three-point estimate recorded of
45 hours. A three-point estimate simply adds up the three estimates and divides by three for the
average.
PMP You’ll see analogous estimating, parametric estimating, and three-point estimates
Coach in the next chapter on project costs too. If you can imagine applying these three
time estimating techniques to cost estimating, you’re on your way.
With all of these estimate types, you can also create a time buffer for the project called a
management reserve or time reserve. This buffer of time accounts for project uncertainty should
any project activities take longer than the activity estimate predicts. Project managers can create
a management reserve for the project schedule based on a percentage of the project duration or
through mathematical analysis using quantitative approaches.
The one danger of using a time buffer is Parkinson’s Law. Parkinson’s Law states that work will
expand to fill the amount of time allotted to it. In other words, if you predict your project will
last 18 months including a two-month buffer project time, your project will magically grow to 18
months because you’ve given the project that time to use.
Learning Objectives
In this lab you’ll explore activity duration estimating techniques. By the end of this lab you’ll be
able to
11. Identify activity attributes
Give an example of activity duration estimates
Explain Parkinson’s Law and management reserve
Create Activity Duration Estimates
Shari is the project manager of the HJK Project for her organization, and you’re serving as a
project management consultant on the project. The HJK Project is an update to the existing office
headquarters for Shari’s company. The office headquarters are 15 years old and are starting to
look slightly dated.
There are four floors in the office building, and each floor has a nearly identical layout, except
for the first floor, which has more common areas. All of the carpet in the building will be
replaced, 546 office doors will be replaced, and 2,000 light fixtures throughout the building will
be updated with new, energy-saving fixtures. Shari has some specific questions about some of
the identified activities in the project.
This lab presented a case study to update the company’s headquarters and then asked you several
hypothetical questions about the scenario and the duration of the project work. Here are the most
likely answers to the questions presented:
1. Shari wants the painting process to be done as soon as possible—hopefully over a
four-day weekend—to avoid disrupting business operations. The painters report that
this isn’t feasible, as one floor of the office building will take six days to paint with
eight painters assigned to the floor. Their estimate is based on their past experience.
Currently Shari has 32 painters assigned to the project activity, but she would like to
increase the number of painters to 64 to reduce the painting activity to just three days.
As a consultant, what do you find wrong with Shari’s reasoning to increase the effort
to reduce the activity duration?
2. You, Shari, and several members of the project team examine the existing doors of the
offices. The project team members remove 10 of the existing office doors and replace
them with new office doors. Given their experience replacing these 10 doors, the crew
believes it will take approximately one hour of labor per door to replace the old office
doors with the new material. How many total hours of labor will be needed for this
activity?
3. Shari would like to test the duration of the light fixture replacement activity using the
same approach as you did with the office doors. The light fixtures, however, must be
replaced by an electrician, and Shari’s company only has two electricians available to
complete this task. One of the electricians, Bob, tests the replacement on 10 lights, and
he estimates that it will take two hours per light fixture to remove, test, and replace the
fixtures. How many hours of labor will this activity take?
4. Bob reports, however, that he and John, the other electrician, can only work 20 hours
each per week on the HJK Project, as they’ve other assignments to attend to. Given
their availability, how many weeks will it take with these two resources to complete
the light fixture replacement activity?
12. 5. Some of the project team members want to pad their project activities duration in case
something goes wrong with the project work. What should you recommend to Shari
rather than padding the individual project activities?
6. What law must Shari and the project team be aware of if they pad the entire project?
What does this law mean for project activity duration estimating?
Lab Exercise 6.05: Developing the Project Schedule
In most projects there are activities that can be done in tandem with other project work, activities
that must be done in a certain order, and activities that can be completed independent of all other
project work. The project management process of developing the project schedule is the analysis
of the project activities, the order in which they can, should, or must happen, and the application
of resources to the activities to determine the best completion for the project. Developing the
project schedule is an iterative activity in project planning that helps the project manager and
project team determine the order and date of completion for all of the project work.
To develop the project schedule, you’ll rely on nine inputs:
Activity list The activities that need to be scheduled
Activity attributes The characteristics, resources, and information about the activities to
be scheduled
Project schedule network diagrams The visual flow of the project activities
Activity resource requirements The resources you’ll need to complete the activities
Resource calendars When the resources are actually available
Activity duration estimates How long the activities will take to complete
Scope statement The project deliverables and requirements the activities will create
Enterprise environmental factors The rules, policies, and regulations that affect the
scheduling of the project activities
Organizational process assets Templates, historical information, and other guidance
that help schedule the project activities
One of the primary approaches project managers use for developing the project schedule is the
reliance on the critical path method. The critical path is the path in the project network diagram
that takes the longest to complete, and it shows the earliest the project can be completed and the
latest the project can be completed. The critical path method reveals float for project work; float
is the opportunity to delay project activities without affecting the project end date. The critical
path has no float available, as any delay of the project activities on the critical path would cause
the project to be late. There are three types of float:
13. Total float The amount of time an activity can be delayed without affecting the project’s
end date
Free float The amount of time an activity can be delayed with affecting successor
activities’ early start date
Project float The amount of time the entire project can be delayed without affecting the
project end date
PMP Consider a project that will require 40 days of consistent effort to complete but
Coach you have 200 days to complete the project at your leisure. Project float, in this
example, is simply 160 days. It’s usually seen on low-priority projects.
Project management information systems can calculate the critical path, but you’ll need to know
how to complete this tedious work for your PMP examination. There are two generally accepted
methods to calculate project float and both work equally well. The following is the most
commonly accepted approach for finding float. Figure 6-2 is a simple project network diagram
where the nodes are the activities, the arrows show the direction of the project work, and the
number above each node shows the duration of the activity.
Figure 6-2: The critical path method reveals float and the early finish date.
In Figure 6-2 note that Activity B is a predecessor to Activities D and E. Activity B must finish
before either of these activities can begin. Activity G, in this example, must have Activities D, E,
and F all completed before it can start. In this example there are three paths to project
completion:
A, B, E, and G, which takes 19 days
A, B, D, and G, which takes 16 days
A, C, F, and G, which takes 20 days
This reveals the critical path as ACFG, as it takes the longest of all the project paths. This should
always be your first step in the critical path method: find the duration of each path. Your next
step is to complete the forward pass. The forward pass simply determines the early start of each
project activity and the early finish for each project activity. You do this by starting with the first
day of the project, the early start, and then determining based on the duration of the project
14. activity what’s the earliest that activity can finish. For example, in Figure 6-3 Activity A can
start on Day 1 and finish on Day 3, as its duration is three days long. This means that Activities
B and C can’t start until Day 4, because Activity A must be completed before either B or C can
start.
Figure 6-3: The forward pass shows the early start and early finish for each activity.
The earliest day that an activity can start is called its early start (ES), and the earliest an activity
can finish is called its early finish (EF). The first activity always starts on Day 1. No other
activity can start until all of its predecessors have completed. The simple formula you’ll use to
determine the ES and EF of each node is ES + activity duration – 1 = EF. Check out Figure 6-3
to see the completed forward pass and the highlighted critical path. Notice on Activity G that the
earliest it can start is Day 14; that’ll be important shortly. Also, notice that the earliest Activity G
can possibly finish is Day 20—the same duration as the critical path. The early finish for the last
activity should equal the duration of the critical path; if not, there’s a math mistake somewhere in
the forward pass. When there are two or more predecessor activities of a successor activity, the
largest of the early finish dates is considered for when the successor activity may begin. In other
words, all predecessors must be completed before a successor may begin.
PMP Duration is sometimes abbreviated as du. In the forward pass formula you can
Coach write it as ES + du – 1 = EF. The reason you subtract one is to account for one
complete day of work. For example, Activity A starts on Day 1 and takes three
days to complete. You work all of Day 1, all of Day 2, and all of Day 3 to finish
Activity A. Using the forward pass formula, you’d take 1 plus the duration of 3
minus 1 for the early finish on Day 3.
Once the forward pass has been completed, you can complete the backward pass. The backward
pass reveals the latest an activity can finish and the latest an activity can start. It’s similar to the
forward pass, except you’ll start at the last activity and use the formula Late Finish – Duration +
1 = Late Start. The late finish date for the last activity is also the early finish for the last activity.
Figure 6-4 is the completed backward pass.
The final step, the easy step, is to reveal which activities have float and how much float is
available. The difference between the early finish and the late finish for each activity reveals the
15. amount of float available for the activity. (Technically, the difference between the early start and
the late start will reveal the same value of float.) Figure 6-5 reveals the amount of float each
activity can have. Notice that the critical path activities have the same late start and early start
values and the same late finish and early finish values. These critical activities cannot be delayed
at all, so there is no float available.
Figure 6-4: The backward pass shows the late finish and the late start for each activity.
In Figure 6-5 you can see the concept of total float. The project must finish by Day 20, or it is
late. If the project manager were to use the one day of float on Activity B, the path ABEG would
now take 20 days to complete, and the path ABDG would now take 17 days to complete. The
amount of available float for Activity D would be reduced to three instead of four. This is
because total float restricts the amount of float that can be used on a path so that it doesn’t affect
the late finish date for the project.
While critical path methodology is the most common approach to scheduling development for
most projects, there’s another approach that’s gaining momentum: the critical chain method. The
critical chain method initially follows the same approach of schedule development by creating
the network diagram and then identifying the critical path. What’s different, however, is that the
critical chain method also considers the availability of project resources to determine when the
project activities can actually occur. For example, in the critical path method there’s an
assumption that Bob the electrician won’t be needed on two different activities at the same time,
when in reality Bob could be needed in two places at once and that would skew the critical path.
The critical chain method considers the availability of resources for all the activities in the
project network diagram to determine the true critical path. When resources can actually do the
work ultimately affects when the project can be completed. The critical chain method doesn’t use
the term “critical path” to define the chain of activities with no float—it calls this the critical
chain. In addition, the critical chain method uses “feeding buffers” for chains of activities that
feed into the critical chain instead of float. It’s basically the same concept, as the dependent
activities have a buffer of time to complete all their activities before the critical chain can move
onward.
16. Figure 6-5: The float is the difference of the late finish and the early finish.
Both the critical path and the critical chain methods allow the project manager to use some what-
if analysis for determining when the project can actually be completed. You can simulate adding
or removing resources, change the sequence of activities, or try other experiments to predict the
best outcome for the project. What-if scenarios can examine any possible event, from power
failures, work stoppage, risks, or other things that may hinder or help the project schedule.
Another term you should be familiar with is resource leveling. Resource leveling limits the
amount of time a resource can work in a given time period. For example, management may tell
you that your project team can only work 30 hours a week maximum on your project rather than
the 40 you’ve planned. With this heuristic of 30 hours, your project is probably going to take
longer to complete because you’re limited to 30 hours per week instead of 40. Resource leveling
is often shown in a resource histogram as in Figure 6-6, where any resource above the 30-hour
heuristic is overallocated and the represented work needs to be reassigned to another resource, if
possible, or carried over to the next time period.
When time is of the most importance, project managers consider schedule duration compression
techniques. The first approach is crashing. Crashing allows the project manager to add resources
to the project to complete as soon as possible. This approach assumes that the project work is
effort-driven, such as painting, construction, or another activity whose duration can be reduced
by adding additional labor. Activities that are of fixed duration, such as testing software
applications, can’t be reduced by adding labor.
PMP Crashing can happen by adding faster resources, such as equipment and
Coach technology—not just people.
17. Figure 6-6: Resource leveling flattens the labor for a given time period.
The Law of Diminishing Returns controls the effectiveness of crashing for most projects. You
can’t exponentially add labor to the project work and exponentially reduce the amount of time to
complete the project work. In other words, you can’t crash your project with so much work that
the project will eventually take just a few minutes to complete. The Law of Diminishing Returns
also dictates the yield, the value, of the project in relation to the cost of the labor you’re adding
to the project work. Even though you can crash the project with additional labor, the time saved
may not be worth the cost of the labor in proportion to the return on the investment. As a general
rule, crashing trades time for cost.
Another approach for schedule compression is called fast tracking. Fast tracking allows two or
more phases (or activities) of a project to overlap rather than to be created in sequence. In
massive construction projects, such as creating a football arena, you can see fast tracking. A
portion of the stadium may appear to be far ahead in its construction while other portions still
have dirt exposed or barely any progress at all. This is fast tracking, as the phases of the project
work overlap in their sequence. Fast tracking does speed up the project execution, but it can
introduce risks in the project work. Should there be errors in the first phase, it can drastically
affect the cost and time invested in the overlapping phase.
Learning Objectives
In this lab you’ll review and experiment with the techniques for developing a project schedule.
By the end of this lab you’ll be able to
Find the critical path in network diagram
Expose the float for certain project activities
Complete a what-if analysis of the project diagram
Evaluate crashing and fast tracking options
Develop a Project Schedule
You are the project manager of the NHJ Project for your organization. You have created the
project network diagram as seen in the following figure. You are now ready to complete
18. schedule development on this network diagram to determine when the project may actually be
completed, to expose float opportunities, and to determine the critical path. Above each node in
Figure 6-7 is the activity duration.
Figure 6-7: The project network diagram shows the order of activities and their durations.
This lab tested your comprehension of finding project float, identifying the critical path, and
evaluating opportunities to delay project work. Here are the answers to this lab:
1. In this network diagram there are five paths to project completion. List all of the
possible paths to the project completion and the duration of each path.
2. In Figure 6-7 complete the forward pass of the schedule analysis. Recall that you can
start on Day 1 for Activity A and use the formula ES + du – 1 = EF, where ES is the
early start, du is the duration, and EF is the early finish.
3. What is the early start for Activity J? What must be true in the project before Activity
J can start?
4. Now you can complete the backward pass in Figure 6-7. Remember, you start with
the last activity’s early finish as the late finish for the project. You can use the formal
LF – du + 1 = LS, where LF is the late finish, du is the duration, and LS is the late
start.
5. What is the latest that Activity F can finish? Why is this important in the project?
6. Now in Figure 6-7 find the float for each activity by finding the difference of the
Early Finish and the Late Finish. Write the float value under each node and circle it.
Remember, there is no float on the critical path.
7. How much float can you use on Activity E?
8. If you use eight days of float on Activity B, how much float can you use on Activity
H?
9. In this project if you wanted to crash the project, what two things would you be
adding to your project?
10. Management has informed you that your project cannot use a resource for more than
25 hours per week on your project work. What is the heuristic called?
11. What will this heuristic likely do to your project duration, and what could you do to
combat this restriction?
19. Lab Exercise 6.06: Controlling the Project Schedule
Once the project schedule has been created, the project manager shifts into a parallel process:
monitoring and controlling the project schedule. This project management process is concerned
with controlling the project schedule by preventing changes to the project schedule baseline. In
other words, once the project has been created and approved, the project manager wants to do her
best to avoid changes to the schedule.
Controlling the project schedule means constantly monitoring the project schedule for adherence
to the project plan. The project manager’s first goal is to work to prevent changes from entering
the project schedule, but this is often unavoidable. When changes enter the project, either
through approved change requests or by errors and omissions, the project manager must react
quickly to the changes and to the effect of the changes on the project schedule. The project
manager will rely on four inputs for this project management process:
Project management plan (specifically, the schedule management plan and schedule
baseline)
Current project schedule
Information about the project work and why the change in the schedule has happened
Organizational process assets, such as historical information, forms, and templates
Armed with these resources, the project manager can evaluate the project schedule performance
and react accordingly. This means, of course, that there’s honest reporting on work performance,
time spent investigating the actual work the project team is completing, and evidence of
requirements and deliverables being created. Milestones, a requirements traceability matrix, and
quality control can all contribute to the evidence that the project is moving toward its
completion.
When there’s a discrepancy between what was planned and what’s being experienced in the
project, there’s evidence of a variance. This schedule variance must be responded to through
corrective actions. You’ll need to take steps to evaluate what the variance is, understand why it
exists, and then plan for the best response to the variance. One approach, which you’ll learn
about in great detail in Chapter 7, is earned value management. Earned value management is a
suite of formulas that attach financial values to work planned and work performed. These
formulas can create a schedule performance index and identify schedule variances.
When you discover variances in your project and you need to make corrective actions, your goal
is to bring project performance back into alignment with the project plan. This can be achieved
through corrective actions, such as crashing the project or fast-tracking the project. Recall that
crashing the project adds people to the effort-driven activities and fast-tracking the project allows
20. entire phases to overlap with other phases. It’s also possible that you may need to adjust your
lead and lag times between project activities to recoup lost time in the project schedule.
When you identify a schedule variance and you take corrective actions, you might also take
preventive actions so that the mistake doesn’t enter the project again. That’s ideal—to learn from
the error and to prevent it from happening again. Whenever a project manager takes corrective or
preventive actions, chances are she’ll also need to update the lessons learned documentation. The
project manager should identify what the variance was, why it occurred, the action the project
manager took, and any other supporting details to the problem and its fix. This will not only help
when it’s time to write the final project report, but also it helps future project managers learn
from what’s happened in this project.
It’s possible that through controlling the project schedule there’s a need for a project change
request. Consider a project that has a fixed deadline but because of some errors in the project the
deadline just isn’t a reality anymore. A change request could be made to trim items from the
project scope in order to still meet the project’s deadline, albeit with fewer deliverables than
originally planned. A change request doesn’t have to be just about the project scope; you could
create a change request to add more time to the project in order to deliver all scope items.
All change requests must pass through the appropriate change control system and integrated
change control. When a schedule change request is approved, the project manager must update
the project management plan to reflect the approved change. The change request can cause the
schedule baseline and the schedule management plan to be updated. Also consider the cost
management plan and needed updates there: if the project manager needs additional time, the
project may incur additional costs for continued resources, facilities, and labor. If the change
request is to crash the project schedule, additional costs are almost always incurred by the
project.
Learning Objectives
In this lab you’ll evaluate a case study and determine the best response to the situations
presented. By the end of this lab you’ll be able to
Evaluate project schedule performance
Create corrective actions for the situations in the project
Determine preventive actions for the project
Update the project management documents
Control the Project Schedule
Mary is the project manager of the JHG Project for her organization. This project is to replace all
printers in her organization with 300 network-enabled printers. The old printers will be removed,
the newer models will be installed on the network, and the software will be added to the users’
workstations and configured for usage. The types of printers to be installed are
21. Series 899 printers These are 50 fast, multidocument printers that can act as printers and
photocopier machines. These printers are to be installed first in the organization.
Series C99 printers These are 50 color-laser printers that are shared on the network for
all users to print to. These printers are to be installed in batches of 10 in an identified
order of precedence for the organization’s lines of business.
Series BW74 printers The remaining 200 printers are network-enabled, black-and-white
printers that all users may print to.
The project team has been installing the Series 899 printers, but they’re off to a late start because
the vendor didn’t deliver the printers as scheduled. The first printer was installed and functional
nearly 10 days late on the project, causing all other project tasks to be delayed. The project team
now has four of the 10 printers installed, and they’re reporting that the installation process is
taking one day longer for each printer than what was planned for.
This lab presented a case study for a project to install printers in an organization. Here are the
most likely answers to the questions presented:
1. Given what you’ve read so far about Project JHG, what mistakes has Mary made with
her scheduling of the printer installations?
2. If you were a consultant on this project, what type of preventive action would you
recommend to Mary?
3. What corrective actions could Mary take right now on this project to move the project
along?
The project team is now finished with the installation of the Series 899 printers, and
they are moving on to the next project activity: the installation of the color printers.
Because the installation of the Series 899 printers is late, the activity to install the
color printers is now also late. The project stakeholders are complaining about access
and training time already reserved. Managers are becoming frustrated because they’ve
scheduled their staff to attend the training session, which now needs to be rescheduled.
4. If you were a consultant on this project, what type of recommendation would you
make for Mary and for the training on the color printers?
5. What could Mary do to bring this project back on track, assuming all of the remaining
printers are available for installation?
6. What preventive actions would you have taken in this project if you were the project
consultant?
