What project management is good at is making the complex simple, or at least manageable. There are, of course, lots of different ways to achieve that goal, many of which are employed during the life cycle of a project.
A project network diagram is one such tool that helps simplify a complex project plan, enabling a project manager to see the big picture of the project. It’s important to have an overview of any project, see when it starts and finishes, and quickly note all the points in-between that intersect and how they work together.
But some might avoid network diagrams, thinking of them as those dense schematics that depict the nodes and connections in a computer network. That would be a mistake. Project managers need tools, and the project network diagram is a great one.
What Are Project Network Diagrams?
A project network diagram is a visual representation of the workflow of a project. A network diagram is a chart that is populated with boxes noting tasks and responsibilities, and then arrows that map the schedule and the sequence that the work must be completed. Therefore, the network diagram is a way to visually follow the progress of each phase of the project to its completion.
Project managers use a network diagram to track the project, allowing them to see the progress of each element. Then they can share the status with the rest of the project group. This is especially helpful for those who better understand information that is delivered visually. For those team members, network diagrams will help with the performance of their tasks and increase the project’s productivity.
Another aspect of the network diagram is that it literally illustrates the project’s scope. That’s because the network diagram collects all the actions and outcomes of the project.
Types of Network Diagrams: ADM & PDM
Network diagrams can be divided into two types, the arrow diagram method (ADM) and the precedence diagram method (PDM).
As expected, the arrow diagram method uses arrows to represent the project activities, with the tail of the arrow being its start and the point the finish. The length of the arrow is the duration of the activity. The arrows connect nodes or boxes that are symbols of the start and finish of the activity in sequence.
In the precedence diagram method, each node or box is an activity. There are arrows, but in this case, they represent the relationship between the activities. That relationship can be one of the following:
- Finish to start: This means an activity cannot start before another activity is finished.
- Start to start: Use this when two activities can begin simultaneously.
- Finish to finish: Use this when activities must finish together.
- Start to finish: Use this when one activity cannot finish until another one starts.
Advantages and Limitations of Network Diagrams
Now that you know what a network diagram is, let’s take a more critical look at the pros and cons.
Pros of Project Network Diagrams
Starting with the pros, network diagrams are a boon to project planning. The technique collects all the necessary tasks that are needed to complete the project successfully. This attention to detail before starting a project will help identify the critical activities and where float, or the time a task can be delayed, might exist.
Having made a network diagram is also a great way to set deadlines and, having all the tasks laid out on one chart, it makes it easier to order the material resources and equipment needed to accomplish them. This description of resources will help with cashflow and assembling the right team. Additionally, having the tasks on a network diagram, and being able to see where they’re dependent on other tasks, can help resolve issues as they arise during the project.
Cons of Project Network Diagrams
There are also limitations. Making a project network diagram takes time and costs money to produce. Also, the network diagram, depending on the project, can be overly complex and difficult to discern visually. That defeats one of its main purposes. Of course, there can be errors when making it or other unknown factors that can influence it outside of the data collected; all of this can make the network diagram misleading and potentially damaging to your project.
Some don’t believe in the necessity of a network diagram, that there are other tools that cover the same ground. For example, there is the Gantt chart, which is also a graphic representation of the project timeline with tasks, duration and dependencies. But a Gantt chart can also allocate resources, update project status and track tasks and time.
Free Tools for Making Network Diagrams
There’s only one way to know if a network diagram is for you or not: try it. Lucky for you there are a lot of free online choices. We picked three of our favorites for you to kick the tires and take out for a ride.
Google has a tool for everything you do, so it almost goes without saying that they have one for network diagrams. Google Draw is completely free (you don’t even have to put in your credit card). It can help you make flowcharts, UML diagrams, entity relations, mockups and, of course, network diagrams.
Data is stored on the Google Drive, but it can also store data on Dropbox and OneDrive. Google draw can import from a variety of different file formats, and it has 27 languages and is easy to share. It’s fast and has real-time collaborative support when connected to a Google account.
On the downside, there aren’t a lot of templates and shapes to choose from. It can be a bit of an uphill battle to learn if you don’t have a design background. Google Draw is best if you want to collaborate with other Google features and only make network diagrams occasionally.
Dia is an open source tool that can be used to make network diagrams. It’s fairly easy to learn and can make basic network diagrams. Dia saves XML formatted documents, which are reduced automatically to save space. It’s available for Linux, Mac and Windows.
Dia is free and makes a good entry-level option for people looking to get familiar with making network diagrams, as well as UML diagrams and flow charts.
The software has a good user interface, which helps users, and is also easy and fast to install because of its small file size. However, the software doesn’t have visual appeal. It’s a bit too simple, and some have criticized it as ugly because of its black and white design, which could be improved with color.
While Gliffy is free, the free version is very limited. If you like it, you’ll probably want to pony up for the full version, with a subscription cost. The cost is tiered, $14.85 every three months for a single user, which can make 200 diagrams, but none of which integrate with Google Drive. A single user business account is $29.85 for three months, which includes unlimited diagrams, but it still won’t integrate with Google Drive. For that you’ll need the business team package, which costs $59.88 a year. The fact that the diagrams are easy to make and collaborate with will probably help with the transition from free to paid.
Gliffy is a web-based app and not suited if you’re looking to make more technical diagrams. However, for a project management network diagram, this is a good first step into network diagramming.
After you’ve given these free network diagramming apps a spin and get a feel for how they handle, take a look at ProjectManager.com, a cloud-based project management software. Our online Gantt chart does much of what a network diagram can do, but also always for real-time collaboration, status reporting and it’s easy to change as the project changes. Try it free for 30-days with this trial.