What is a Network Diagram in Project Management?

Updated Aug 3, 2022.
Network-Diagram-Infographic

As a project manager, you need to know how to properly manage the different types of projects. The bigger a project is, the more complex the management process is. Managing a project involves planning tasks, organizing schedules, and juggling dependencies, which can be quite a handful for anyone.

Many project managers tend to get confused at the project initiation stage. The main cause of confusion is how to prioritize project activities. There is a need to establish a logical relationship among project tasks so that everyone involved can understand the sequence of tasks or activities in the project. 

One of the biggest project management challenges project managers face is delivering projects on time. Whether you are a project manager or a member of the project team, creating a network diagram can help you plan and schedule your projects more accurately. 

In this guide, you will learn how to prepare a network diagram to properly plan and schedule your project activities.

Let’s get started.

What is a Network Diagram?

A network diagram is an efficient and orderly project scheduling tool that provides a clear visual outlook in a logical manner of the relationship between various project tasks. Your network diagram is grossly dependent on your project’s tasks and events.

To depict the inter-connectivity of the schedules and work programs of the project, the project diagram makes use of boxes and arrows in a chart-like form. This tool can act as an effective tracking tool for the project’s progress and success rate. 

The boxes or nodes utilized in a network diagram represent the various tasks and work programs of the project while the arrow acts as a linking mechanism to illustrate inter-relationships among the various tasks and work programs. 

Every network must have a start and finish task and all other tasks and activities are defined by these two tasks. You have to create a separate dependencies chart before creating your network diagram. The reason why is that the network diagram utilizes project dependencies in creating the relationship between tasks.

Types of Project Network Diagrams: Arrow Diagram and Precedence Diagram

Project networks basically can come in two types and they both are efficient tools in connecting project tasks together.

1. Arrow Diagram Method (ADM)

The arrow diagram method is a representation tool that utilizes the use of arrows to represent activities that are linked to the project to link them together. ADM comes with a lot of limitations to project management and is sparsely being used in project management. 

Each arrow acts as an efficient connector between two boxes or nodes in sequential order. The starting node is termed the “i-node” while the ending node is termed the “j-node”.

This type of project network diagram shows efficient task or activity dependencies and represents the relationship between the project start to finish. 

Arrow Diagram Method Example
Source: Projectcubicle

Features of the Arrow Diagram Method

  • An arrow tail that points out the start of the project activity
  • An arrowhead that points out the end of the project activity
  • The arrow length represents the duration of the project task or activity

Pros of Arrow Diagram Method

  • Easy to create and implement
  • Gives a clear understanding to the project team
  • Requires little or no formal training

Cons of Arrow Diagram Method

  • No adequate provision for inclusion of lead and lag times for project activities depicted in their nodes without creating new nodes.

2. Precedence Diagram Method (PDM)

The precedence diagram method is a system of network diagrams that utilizes the use of nodes, representing activities or tasks and arrows, representing relationships between tasks. 

This project network diagram is more effective than the arrow diagram. The arrow can represent either the finish to start, start to start, finish to finish, or start to finish relationships. 

Pros of Precedence Diagram Method

  • Better and more accurate estimation of project completion time
  • Adequate provision for the inclusion of lead and lag times for project activities

Cons of Precedence Diagram Method

  • Takes a longer time to create as compared to the arrow diagram method

Benefits of Using Network Diagrams

Network diagrams offer a wide range of benefits to project managers. They assist in making the project scheduling process relatively easier and more efficient.

1. Visual Representation of Project Progress

When creating a network diagram, ensure it can be interpreted by all stakeholders. Your network diagram is an efficient tool in tracking the progress of your project tasks and activities as they are all visible on the network diagram chart. 

The progress of your project about tasks can be adequately visible through your network diagram. This ensures you have a visual idea of the progress made as regards task implementation as well as the overall progress of the project.

2. Establishing Project Workflows

Project workflows are important for ensuring interconnectivity among project tasks. Network diagram uses appropriate tools in establishing workflows among project tasks and key activities. 

Establishing project workflows help ensure the project process goes on smoothly and is devoid of issues that might want to impede its successful completion.

3. Tracking Dependencies and Potential Bottlenecks

Network diagrams are efficient tools in spotting potential issues likely to plague the project implementation process by merely looking over a chart. 

Your network diagram maps out the necessary steps and routes to be taken for project implementation. With this project scheduling tool, you can easily know if your project process is diverting from the set-out route. 

Network diagrams can also be used to track task dependencies as they are connected by arrows in your chart. These dependencies can be shared with other stakeholders in the project process. A network diagram helps to keep everyone in the loop and adequately informed about the happenings around the project process.

4. Improves Project Efficiency

Visual representation of data to your project team improves better comprehension and understanding of the project plans and tasks to be implemented. In simpler terms, network diagrams are efficient boosters of project productivity and performance.

They ensure the stress usually associated with the study process that your project team would have undertaken without the aid of network diagrams has been adequately taken off.

How to Draw a Project Network Diagram

In drawing up an efficient and effective project network diagram, some key requirement processes need to be adhered to to ensure your network diagram meets its desired target in delivering good results.

1. Define Project Activities, Schedule, and Dependencies

Defining your project activities, schedule, and dependencies are the building blocks of a properly-crafted project diagram in project management. 

The first step in creating a project network diagram is to list out all the project activities and tasks to be embarked on during the project process and allocate the time required for their successful implementation. 

Your allocated time should be feasible and visible in order not to put stress on the project team. Also, arrange the activities in a way that activities that are dependent on the completion of other activities are grouped and tagged together.

2. Display all Activities in Nodes with their Duration

After successfully listing and arranging your project tasks and activities according to dependencies, the next step is to input all activities in nodes. Nodes are rectangular boxes in your network diagram that houses project activities. The duration for each activity should also be included alongside each activity.

Define the dependencies that exist between activities and group them side by side. The task on which another task depends is called predecessor while the task-dependent on another task is identified as the successor and they are linked together by an arrow. 

Link Activities based on Dependencies
Source: Tiemchart

4. Adequate Planning of All Activities

You need to make adequate preparations for the successful completion of the highlighted activities. This can be either through planning from the predecessor task to the successor task, or backward planning from the successor task to the predecessor task. 

Both planning methods ensure all the necessary parameters are adequately covered in ensuring the activities meet their set deadline requirement.

5. Determine the Critical Path

The critical path of any project is the path of activities with the longest expected completion time from the start of the project to the end. This path is the most critical as the minute of delays among any of the activities on this path will lead to a delay in the project’s scheduled completion time. 

Project managers need to keep a keen eye on these activities as they are paramount to the project reaching its scheduled deadline. 

Martin Luenendonk

Editor at FounderJar

Martin loves entrepreneurship and has helped dozens of entrepreneurs by validating the business idea, finding scalable customer acquisition channels, and building a data-driven organization. During his time working in investment banking, tech startups, and industry-leading companies he gained extensive knowledge in using different software tools to optimize business processes.

This insights and his love for researching SaaS products enables him to provide in-depth, fact-based software reviews to enable software buyers make better decisions.