Comparing JavaScript PERT Chart and Gantt Chart
When developing a web application for effective project management, it is vital to make sure that your app includes the proper tools, enabling end-users to visualize the scope of a project and track its progress. At this stage, many web developers face the problem of choice, as nowadays there are many visualization tools that generally meet those criteria. The most notable of them are JavaScript PERT and Gantt charts.
What is the difference between them? It is a common question that we hear from web developers who are seeking a proper visualization component for their projects.
Indeed, it seems like a reasonable question, because you can see a lot of common points when comparing Gantt charts with PERT diagrams. Both tools vividly show project tasks, define task dependencies, and determine the critical path. So why not just implement any of them in your app and put the matter to rest? But it’s not that simple.
In this post, we’re going to shed light on how these charts can be helpful in project management, describe their peculiarities, and find out what are appropriate use cases for each of them.
What is Gantt Chart in Project Management
Gantt charts have been known to the business world for more than a century. During that time, this tool has evolved from a basic bar chart drawn on paper to feature-rich and elaborate data visualization functionality widely implemented in web apps for managing projects of all types and sizes.
In essence, a Gantt chart is a robust instrument that provides a visual representation of project tasks along a given timeline. The tasks are displayed in the form of horizontal bars and the length of those bars specifies the duration of these tasks. Using Gantt charts all persons involved in the project can get a clear picture of the project status at any moment, the precise timing of tasks and their dependencies, milestones, and much more.
Moreover, modern Gantt chart components such as DHTMLX JavaScript Gantt allow enriching web apps with extra functionalities such as resource management, critical path analysis, additional task constraints, auto-scheduling, task grouping, or usage of custom content atop Gantt. Thus, after implementing a Gantt chart component into a web application, project managers (PMs) get at their disposal an advanced tool with enhanced capabilities to meet all deadlines and guarantee the project success.
The image presented above is the example of DHTMLX Gantt chart for the project in the construction industry. In addition to standard sections of the Gantt chart (data grid and timeline), you can see the resource diagram in the lower part of the chart. This diagram is an extremely helpful tool for effective resource allocation and workload balancing.
A Gantt chart looks like an all-embracing solution for managing projects, but let us get acquainted with a PERT chart and estimate its capabilities.
What is PERT Chart in Project Management
A PERT Chart, also known as a PERT Diagram, is a charting tool based on the PERT (Project Evaluation and Review Technique) method and intended for planning, arranging, and handling tasks within a project. But most importantly, it allows specifying the execution time for each task and the time required for the fastest possible implementation of the whole project i.e. its critical path.
When it comes to estimating this important parameter, the PERT method may seem similar to the standard critical path method (CPM), but they are not identical. The main distinctive aspect of a PERT chart is that it uses three time estimates instead of one in CMP:
- optimistic
- pessimistic
- expected
This estimation approach enables PMs to establish the most probable project schedule.
A standard PERT chart template consists of nodes referring to milestones. The nodes are connected by arrows that identify various project tasks. The chart also vividly shows possible order of tasks execution (one by one or simultaneously). PERT charts also give a great opportunity to better understand the work breakdown, optimize resources by specifying slack times for each activity as well as estimate potential risks related to the project.
Check out a basic PERT chart example built with the use of the JavaScript diagram library by DHTMLX:
In this image you can see a basic project scheduling of a hardware manufacturing process with several networks of interconnected tasks, dividing the project work into 4 segments (specification development, hardware manufacturing process, software development, preparation of manuals). The sequence of project activities highlighted in red presents the most vital tasks that must be completed in time to meet the project deadlines (critical path of the project).
Most frequently, PERT charts are applied at the planning stage of large-scale and complex projects, which do not include any precise details on project activities and their approximate durations.
Now let us delve a little bit deeper and see the main differences between these tools as well as advantages and disadvantages over one another.
PERT Chart vs Gantt Chart: Differences, Pros and Cons
Both Gantt charts and PERT charts are widely-used tools for visualization of the project life cycle. However, there are some important factors that should be taken into account when choosing the right instrument for your project.
- Data presentation and application stage
The first and the most notable difference between PERT and Gantt chart is how they showcase the project information. Gantt charts present project tasks and timelines in the form of a bar chart, while PERT charts are organized as a network diagram. Another difference between these tools is the stage of a project at which they are commonly used: PERT charts come in handy at the planning stage, while Gantt charts are more preferable when the project is underway.
- Complexity and readability
The complexity level of a given project i.e. the number of tasks and the level of dependency between them plays a major role when selecting the proper visualization tool. Smaller projects are perfect for using Gantt charts, while big and complex undertakings are better executed with the use of PERT charts.
One significant advantage of Gantt charts over PERT charts is clearness. Gantt charts vividly display both task and overall project timelines, allowing the whole project team to easily check on the current project status. PERT charts, in turn, are less straightforward and people unfamiliar with this approach may spend considerable time figuring out how to read a PERT chart.
- Illustration of task dependencies
In some cases, PMs give preference to PERT charts over Gantt charts because they are more comprehensible when it comes to showcasing task dependencies in the project. Gantt charts are also not bad at showing dependencies between various project tasks, but they can become not very convenient to use when the project gets overwhelmed with too many tasks. PERT charts, in turn, can plainly display complex projects including any number of tasks and dependencies between them.
- Timeframe clarity
One of the most noticeable disadvantages of PERT charts is that this planning tool does not show all project tasks on the timeline, thus the project team may fail to notice that some unfinished tasks come closer to their deadlines. Gantt charts do not have this drawback, as the horizontal axis on them clearly displays the current status of all project tasks on a certain date.
DHTMLX JavaScript PERT Diagram and Gantt Chart
If you have chosen the right tool for your project, then it’s time to embark on the development. DHTMLX JavaScript libraries enable web developers to implement both Gantt charts and PERT charts in project management applications.
Fully customizable and intuitive Gantt charts can be added to a web app using DHTMLX Gantt. This feature-packed JavaScript library is compatible with the most popular frameworks and server-side technologies. But developers will have to devote considerable time to configuring this library in accordance with the project needs. It is not hard to initialize a basic Gantt, but it will certainly require some time to get a clear understanding of all methods and properties of the comprehensive API and add all necessary functional capabilities. But don’t get discouraged. We provide detailed documentation and vivid samples to speed up your learning process.
Useful links to help you get started with DHTMLX Gantt:
When it comes to adding a basic PERT chart to any project, developers can do it quickly and easily using DHTMLX Diagram. Our component offers a variety of predefined shapes and the possibility to add custom shapes for building a simple and good-looking PERT chart. Moreover, it’s possible to set up a live Diagram editor so that end users can create and edit PERT charts on the fly. The right panel of the editor has all the necessary options for editing the chart via UI.
Useful links to help you get started with DHTMLX Diagram:
Today, JavaScript Gantt chart and PERT chart have become popular tools in software engineering. Implemented in web applications, they contribute to the timely and successful completion of any project. Despite some limitations, both these components can be great assets to any project management toolkit.
