What Is a Network Diagram in Project Management?

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Last updated on
11th Jul, 2022
12th Oct, 2021
What Is a Network Diagram in Project Management?

In this day and age of complex projects that span geographies, time zones, rapidly changing technology and requirements, having tools that enhance efficiency can greatly increase the chances of project success. Project Management tools that help to better manage resources and budgets and which help to track project progress are a boon for stressed and overworked project managers. In order to be a good project manager, one must have a thorough understanding of tools required and conflict management.

One such tool is the network diagram in project management that gives a visual representation of the workflow of a project, thus allowing users to track the progress of the project at any time. In this blog, we look at the various characteristics and benefits of network diagrams in project management.

Here is an article on  project description.

What is a project network?
Project Network

Source: Hygger.io

Visual aids like project networks have been widely used in project management to help project managers and team members stay clued in on the progress of projects and share it with all those involved in the project.

 A project network, also called project activity network, is a graphical description of the sequence in which the terminal events or milestones of a project must be completed. The project network is similar to a flow chart. The terminal events of the network represent activities and deliverables derived from the work break down structure and are arranged sequentially like in a flowchart

Project Networks can be created using techniques like Gantt Charts, PERT charts, and Critical Path Management. There are multiple paths in the project network but each terminal element must lie on only one path of the network. 

Get to to know more about agile vs traditional project management.

Project Management Network Diagram

Network diagrams are used by Project Managers to track the progress of activities during the course of the project. In other words, they represent the workflow of the project. Those involved in the project can get a bigger picture of the activities and timeline of the project. Project network diagrams help everyone involved in the project to visually track the progress of every phase of the project from its inception to its completion. The network diagram is a chart and contains boxes and arrows. The boxes denote tasks and responsibilities, and the arrows denote the sequence in which the tasks must be completed and the schedule.

The network diagram also shows how an activity relates to the other and the sequence of activities to be conducted. The precedence of activities as shown in the diagram is important, as some activities have to be completed before the next one starts.

Network diagrams also help to determine the impact of finishing tasks early or late, on the overall project. Managers can use network diagrams to better allocate resources and schedule their timelines.

But creating a network diagram requires a lot of planning. All activities must be identified and estimated as leaving even one task out from the network diagram can cause a cascading effect on the projected schedule, commitments, resource allocation and cost of the project.

Know more about characteristics of project management.

Types of Network Diagrams

Project network diagrams can be of two types:

1. Arrow diagram method (ADM): 

As the name suggests, this type of diagram uses arrows to depict terminal elements/activities.  The length of the arrows typically represent the duration or time taken for completing a particular activity or task. The tail shows the start of the task while the head shows the completion of the task. The order of activities or their precedence is represented by circles that are connected by arrows.
The diagram may also contain dummy tasks that are used to show the inter-dependency between tasks. Dummy tasks, though, do not represent any real sequenced activity but they are more of check-points or milestones that may need to be completed on the way to moving forward with the next task.

Advantages of the PDM are as follows:

  • Simple to create
  • Easy to understand
  • Helps track project schedule
  • Helps in ‘what if’ analyses

Arrow Diagram Method (ADM)
Source: www.workzone.com

2. Precedence diagram method (PDM): 

PDMs too, like ADMs are used in project management. The activities are represented by boxes or nodes. The arrows connecting them represent the relationship between the activities. Depending on the precedence of the activity, the arrows represent different relationships. For example, an arrow can be used to show that an activity cannot start before the completion of its predecessor or if both activities can be started simultaneously.

Here are the four ways of developing the diagram and connecting the tasks based on precedence:

  • Finish-Start: An activity has to be completed before starting the next activity
  • Start-Start: Both activities can start together
  • Finish-Finish: Both tasks need to finish together
  • Start to Finish: This is a rare dependency and requires one activity to start before the other can be finished

The duration for completion of the particular activity can be mentioned over the arrow connecting the activity to its successor.

Advantages of the PDM are as follows:

  • Makes planning more efficient by focusing on relationships and dependencies between activities
  • Helps identify missing tasks
  • Critical tasks can be identified and prioritized
  • Helps in evaluating alternatives
  • Helps to share project timelines across the team and with stakeholders
  • Helps the project manager to better manage and control the project

Precedence Diagram Method (PDM)

Source: Acqnotes.com

Benefits of a Network Diagram

Being visual aids, network diagrams have a lot of advantages, such as:

  • Aid for tracking projects
  • Sequential arrangement of project activities helps to better plan and schedule
  • Helps to visually monitor project status
  • Detailed representation helps identify critical activities
  • Helps identify risks in terms of time delay
  • Helps to identify co-dependent activities for tasks
  • Helps resolve issues that may arise in the course of the project
  • Can be shared with project team members
  • Useful for project team members who can better understand visual representations
  • Increases project productivity
  • Represents project scope on a macro level
  • Used to create project schedule
  • Helps in budget allocation
  • Helps to establish clear deadlines
  • Used to estimate the duration of the project
  • Helps in resource allocation as items are clearly represented
  • Accurate description of activities helps in getting funding and in getting together the right team
  • Enhances efficiency as teams are well aware of deadlines

While there are a whole lot of advantages to network diagrams, there are also certain disadvantages:

  • Can be an expensive tool to create
  • May involve too many activities and tasks and may be difficult to understand
  • There may be errors when creating the network diagrams
  • Network diagrams can be misinterpreted that can lead to serious errors in the way the project is executed
  • May get effected by external factors

Developing a Network Diagram

Developing a network diagram is not an easy task, in the sense that it requires a whole lot of homework to be done before being created. Project Managers or others who are involved with every aspect of the project and know the project requirements at a very detailed level are ideal candidates for creating the network diagram.

The network diagram requires the involvement of people responsible for the different activities of the project. A well-done network diagram smoothens out the project path and ensures early identification of issues and bottlenecks.

Requirements for creating a network diagram 

As mentioned above, the creation of a network diagram requires a whole lot of pre-planning. The following information must be at hand before the network diagram is created:

  • The start and end points of the project must be identified and defined
  • All project activities must be identified
  • Accurate estimation of the completion time of each activity must be carried out
  • Dependencies must be identified

Best Practices to be followed while creating Project Network Diagrams

Network diagrams when created accurately can bring in a whole lot of benefits. Let’s look at the best practices to be followed while making the network diagram.

  • Use standard network diagramming symbols that are universally known and accepted
  • If using different symbols, make sure they are correctly defined
  • Always use straight arrows
  • Avoid crisscrossing arrows
  • Use minimum number of dummies
  • Arrows should be used from left to right
  • Use just one starting point or start event and one culmination point or end event
  • Use tools for more accuracy and lucidity
  • Make sure your diagram contains relevant and up to date information
  • The network diagram must contain the right amount of detail
  • Ensure that the data used to create the network diagram is accurate and well managed

Network Diagram Tools

There are several network diagramming tools available that are precise and make our job easier. Some of them include:

  • Microsoft Visio
  • Google Draw
  • Lucidchart
  • ConceptDraw Diagram
  • InterMapper
  • EdrawMax and more.

To conclude:

A picture speaks a thousand words! And what could be of more help to a project management team than a picture that helps one understand the whole project?

By providing a diagrammatic representation of the events, activities, structures, and processes, the network diagram helps all those associated in the project to understand the project at a micro level. Project managers especially, have found network diagrams to be valuable tools in managing projects and ensuring their success



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