This document discusses leveraging manual and software-generated network diagrams in project management. It analyzes two sample projects using Microsoft Project and manually-generated network diagrams. While MS Project automatically generates critical paths, it does not show activity slacks. Manually drawing network diagrams provides activity slacks, enabling identification of non-critical paths that can be used to level resources. This allows borrowing time from non-critical activities to apply to lagging critical activities, keeping projects on schedule. The document recommends teaching both MS Project and manual network diagram skills for optimized project management performance.

1. Leveraging Manual and Software-Generated Network Diagrams:
The Microsoft Project Experience
Dr. Kene David Ewulu, EdD, MBA, MS, LEED-AP, PMP.
Adjunct Professor: Organizational Leadership, Business, & Project Management
Lead Coach: KDE Leadership, LLC.
June 2018

2. Abstract
As a project management and leadership professor with the task of instructing undergraduate and graduate
students on foundational and complex project management principles, I have observed that a good number
of my students face a unique set of challenges with utilizing the Microsoft Project software in managing
projects. This includes both novice and practicing project managers in my ground-based and virtual
classrooms.
While compiling a work breakdown structure (WBS) and generating Gantt Charts for simple and complex
projects is relatively simple, I observed that certain critical elements needed for optimizing planning and
allocation of resources to tasks were difficult to produce. As the software produces a network diagram with
a critical path outlined (often in depicted in RED), slacks for each of the project’s activities are not included
within the activity boxes. This leads to guesswork from students and inexperienced practitioners on how to
identify the most critical activities and optimally select non-critical activities for resource-levelling purposes.
This abstract aims to show how this discrepancy occurs, using two selected projects, and to guide readers
on how to manually generate network diagrams that contain early-start (ES) and late-start (LS) values,
activity slacks, and ultimately permutate total project float. With this, the project manager can accurately
produce baseline plans and network diagrams to facilitate the future tweaking of schedules and resources
during project execution.

3. Introduction
The advent of project management software has revolutionized the management of projects in 21st
century organizations. The ability to set up project scope, costs, schedule, and the project management
plan before the commencement of project execution provides a baseline for monitoring and controlling
them, and a guide to team members and other project stakeholders.
The Microsoft Project software is one very commonly used software; with its smooth interface with
the Microsoft Office Suite of tools – MS Word, PowerPoint, and Excel. Of course, there are other powerful
project management software out there, but this paper focuses on the comprehensiveness of MS Project
regarding network diagrams and identifies some of its common challenges. Slacks and float help project
managers determine how much room they have at their disposal to maneuver and tweak their projects
when resources are scarce for critical activities, and which human resources to assign activities to based
on their availability, leaves of absences, cost per hour, and family-work balance considerations. As such,
accuracy at this step of the process is crucial to the success of any project.
In project management classrooms and during executive coaching sessions, this practitioner
discovered that these same challenges abound, and that students were not able to comprehensively
answer project-related questions that involve resource-levelling through either crashing or fast-tracking
techniques. In the quest to effectively pass on the ability to identify slacks and floats, manually-generated
network diagrams were embraced. The leveraging of forward and backward pass calculations enabled
students and moderately experienced project managers to clearly identify activity slacks and see how to
‘borrow’ idle human resources for optimal periods of time to apply to potentially lagging critical path
activities.
This paper will explain the dynamics of slacks, floats, and critical path activities by performing MS
Project and manual network diagrams on two randomly selected projects from approved project
management texts and comparing their outputs with each other.

4. Body
Planning a project cannot be accurately done without first understanding certain concepts within
the network diagram. The network diagram shows the graphical dependencies of activities, especially as
certain activities must be concluded before others can begin, while some other activities do not have that
relationship. The Work Breakdown Structure (WBS) is a “framework used for further planning, execution,
and controlling of projects, and to progressively divide project deliverables into smaller pieces”
(Kloppenborg, 2015, p.151). As a project manager formulates the WBS, he or she lists out the individual
activities that must be performed to take the project from inception to completion, including the duration of
each activity, as well as the activities that must be concluded before subsequent ones can start
(predecessor activities).
Once this is completed within the MS Project platform, you can automatically generate the Gantt
Chart by clicking on the Gantt Chart icon; this shows you a horizontal histogram or bar chart that indicates
start and completion dates, as well as the resource personnel assigned to the activities. The Gantt Chart is
described as “a bar chart of schedule information where activities are listed on the vertical axis, dates are
shown on the horizontal axis, and activity durations are shown as horizontal bars placed according to start
and end dates” (Kloppenborg, 2015, p.192). MS Project can also automatically generate the network
diagram by clicking on the Network Diagram icon; this diagram shows the activity dependencies, and
clearly identifies the critical path in RED. The critical path is defined in project management terms as the
longest possible path from inception to completion, and/or the path where all activities have zero slack or
the shortest possible time (Kerzner, 2013, p.600). By ‘zero slack’ we mean those activities that have no
extra days added on; this means that it is crucial for them to be completed within the stipulated time,
otherwise the project completion date will be delayed. Slack is defined as “the amount of time an activity
can be delayed and not delay the project” (Larson & Gray, 2014, p.173).
To enable us to assess these phenomena and ascertain the proficiencies of both outputs, the
author has selected the following project samples from popular college and graduate school project
management texts.
Project Samples
Project 1 Description - Greendale Stadium Project (Larsson & Gray, 2014, p. 203)
This is a baseball stadium project that comprised of twenty activities with designated activity
durations and dependencies. Students were required to formulate a work breakdown structure (WBS)
based on the available data, generate a Gantt Chart and Network Diagram, and then utilize these tools to
answer questions ranging from identification of critical paths, slacks, total float, and activities that could be
tweaked to release idle resources for resource-starved critical activities. For the purposes of this paper,
Microsoft Project-generated WBS, Gantt Chart, and Network Diagram, as well as a manually-generated
Network Diagram were produced from the available data:

5. MS Project-Generated WBS and Gantt Chart

6. MS Project Generated Network Diagram
As can be observed from the MS Project-generated network diagram above, the critical paths are
depicted in RED. However, on closer examination of the activity boxes or nodes as they are termed in
project management circles, the activity boxes are missing one vital information that is required for accurate
analyses and scheduling of resources for the tasks: slacks or floats for each task. Even though it is possible
as common practice to intuitively add buffers between activities to act as floats, when time is of the
essence, this becomes wasteful when considering the overall cost and completion period of the project.
One way to work around this is to manually design a network diagram that will not only show the critical
path, but also identify the activity slacks and enable the project manager calculate project float, thereby
determining who to assign to each task based on their hourly rates of compensation, their availability, and
their skill levels. A manually-generated network diagram for the Greendale Project is shown below:

7. Manually-Generated Network Diagram
After performing the forward and backward passes on this network diagram, you obtain the slacks
for each activity by finding the difference between the early and late starts. This is the difference between
the top left number and the bottom left number in each activity box or node. Tracing the critical path
requires the project manager to connect all the activities with zero slack; for this project, there are two
critical paths, and they are ‘activities 2-5-6-9-10-14-15-20’ and ‘activities 2-5-6-7-10-14-15-20’.
The interesting thing here is that these sequences of activities are the same sequences depicted in
RED within the MS Project-generated Network Diagram. In other words, the linking of activities with zero
slack equates to the identification of the longest possible duration from the beginning of the project to the
end; this is the critical path, or in the case of this project, these are the critical paths.
Visualizing each activity slack allows us to plan. We determine which activities have idle time or
resources (those NOT along the critical path), and how much time or resource we can borrow from non-
critical activities to apply to those critical tasks running behind schedule.

8. Project 2 Description – Product Upgrade Project (Kloppenborg, 2015, pp.179-188).
This is a product upgrade project with seven activities. The activities range from determining product
features to acquiring prototype materials, producing the prototypes, designing market campaigns, designing
graphics, conducting the marketing, and performing sales calls. The MS Project-generated Gantt Chart is
presented below:
MS Project Generated WBS and Gantt Chart (Project #2)

9. MS Project Generated Network Diagram (Project #2)
As in the first example, the critical path is depicted along the RED path, and includes activities:
determine new product features (A), design marketing campaign (D), conduct marketing (F), and perform
sales calls (G). However, closer attention to the details of the activity boxes reveal that the activity slacks
are not generated, meaning that we are not able to calculate total project float, nor are we able to perform
any resource levelling actions accurately.
A manually generated network diagram is produced below, with the activities represented by
alphabets as follows:
A – Determine new product features
B – Acquire prototype materials
C – Produce prototype
D – Design marketing campaign
E – Design graphics

10. F – Conduct marketing
G – Perform sales calls
Manually-Generated Network Diagram (Project #2)
(This diagram was taken from Contemporary Project Management, 3rd Ed., by Timothy Kloppenborg,
Centage Learning, 2015, p. 188).
The critical path is identical to that generated by the MS Project software (see the RED arrows),
and is traced from activity A to activity D, to activity F, and finally, to activity G. Again, you will observe that
these activities are those with “zero” slack, which also can be traced as the path or route with the longest
possible duration.

11. We will now look at the trends and forecasts occasioned by the activity slacks and total project float
as revealed by the manually generated network diagram, and the planning information they provide for
project managers during the planning, execution, and monitoring phases of their projects.
Network Diagram Variances and Inferences
MS Project generated Work Breakdown Structures (WBS) have the capacity to give project
stakeholders a visual presentation of the activities, dependencies, schedules, human resources, and the
accompanying costs associated with the project. The histogram displayed forms the planning and
supervision baseline for the project, giving project team members something to compare with progress and
project status during execution. The accompanying MS Project software generated network diagram also
identifies the critical path for the project.
However, manually calculating a network diagram allows us to leverage the activity slacks of
activities NOT along the critical path to complete critical activities that for whatever reasons, are lagging
behind and need an injection of more human resources to keep to established schedules of completion.
Project 1 - Greendale Stadium Project
Reviewing the manual network diagram for this project, you will notice there are five other paths
that do not align with the two identified critical paths. The activities on these five paths are called non-
critical activities, and you will notice they all possess some slack. For the purposes of this paper, we will
select paths 2-3-8-20 (with a total float of 495 days), and 2-3-7-11-20 (with a total float of 365 days). From
these two paths, we can borrow up to the maximum extra days available on each activity and apply those
periods and the resource personnel attached to therein to any schedule-challenged activity along the
critical path. Maximum periods of 210 days from activity #3 and 275 days from activity #8 can be borrowed
from path 2-3-8-20, while maximum periods of 210 days from activity #3 and 155 days from activity #11 can
be borrowed from path 2-3-7-11-20.
Project 2 – Product Upgrade Project
The manual network diagram for this project reveals two other paths that do not align with the
critical path. These non-critical path activities are A-B-C-G with a total float of 20 days, and A-D-E-G with a
total float of 20 days. Again, we can borrow from activities B (maximum of 10 days of slack), activity C
(maximum of 10 days of slack), and/or activity E (maximum of 20 days of slack) and apply these periods
and their attendant human resources to critical schedule-challenged activities along the critical path A-D-F-
G.
Real World Applications and Conclusions
The capability of borrowing time and human resources from non-critical path activities and applying
them to schedule-challenged critical path activities means that the manual network diagram is a “living
thing”. It changes during project execution due to the project manager’s need to leverage idle resources.
Critical paths can change from the baselines obtained during the planning stages of the project. This
levelling of resources leads to a criticality of almost all paths along the network diagram, meaning that non-
critical activities suddenly have less available, idle resources (less slack). The project manager therefore
uses up more time, utilizes marginally more money (because the erstwhile idle resource personnel may be
paid for the extra work they are now mandated to do), and most importantly, keeps to the original

12. completion date planned into the project from the onset.
Does this now mean that MS Project should not be used for these projects? Far from it, because
there are so many other reporting and tracking features that automation through MS Project affords the
project manager. Furthermore, uploading the continually changing Gantt chart and network diagrams to a
central virtual site allows other stakeholders access to progress reports, and helps keep team members on
the same page.
It is recommended that project management practitioners be taught the skills required for utilizing
MS Project, as well for manually generating network diagrams to ensure optimized performance in the field
and in the classrooms.

13. References
Kerzner, H. (2013). Project management: A systems approach to planning, scheduling, and controlling (11th
ed.). John Wiley & Sons, Hoboken, NJ.
Kloppenborg, T. (2015). Contemporary project management (3rd ed.). Centage Learning, Stamford, CT.
Larson, E. & Gray, C. (2014). Project management: The managerial process (6th ed.). McGraw-Hill, New
York, NY.