Pert Chart vs Gantt Chart

Pert Chart vs Gantt Chart

If you’re unfamiliar with PERT and Gantt charts in product management, you’re already missing out!

An excellent product manager has an engineer’s brain, a designer’s heart, and a diplomat’s tongue.

Managers create schedules because they must also control the timing of all operations. They choose jobs to be done during the manufacturing process, allocate tasks to workgroups, and set deadlines for task completion. They also ensure that resources are accessible when and where they are needed. 

Several scheduling methods are available, and the Gantt and PERT charts are two of the most common.

Who said that being a product manager was easy peasy? 

Product management requires careful planning and scheduling, and a product manager should be familiar with the many chart types available to accomplish this purpose. 

A well-planned project aims to do more in less time. It maintains consistency, improves quality, and reduces financial and resource allocations by ensuring you utilize resources to their full potential. 

Gantt charts and PERT charts are the two most used charts for visualizing an organization’s online and offline work.

In several companies, the term PERT is considered similar, if not identical, to Gantt Chart

It tends to come up in conversations when people discuss project management and lean practices.

This article will explain what a PERT and a Gantt chart are and their beginnings in product management

I’ll go through their differences and show you some examples of how you can utilize them in project planning. 

So stay with me and follow along!

PERT Charts

Origin of PERT Chart

Many people know how to make and utilize PERT charts, but how many are familiar with the history of this project management tool and how it relates to other scheduling concepts?

PERT was created to do planning and scheduling large and complicated projects easier. 

It was built in 1957 for the US Navy Special Projects Office to help with the Polaris nuclear submarine project. 

Various industries used it. One early application was for the 1968 Winter Olympics in Grenoble, which used PERT from 1965 until the Games opened in 1968.

This project paradigm was the first of its kind, a scientific management revival developed by Frederick Taylor (Taylorism) and refined by Henry Ford (Fordism). 

PERT and DuPont’s critical route technique were developed about the same time.

This history is fascinating, right?

A network diagram is another name for it. Although many use the Gantt charts and PERT charts frequently together, the Gantt chart is over 40 years older than the PERT chart. 

Despite its earlier use, the Gantt chart gained popularity during the 1950s, when the first PERT charts were adopted.


  • Float/slack = The amount of time you can postpone a task without the entire project getting delayed.
  • Lead time is the amount of time allocated to an activity without causing other tasks to be delayed.
  • The lag time is the earliest a task can follow the previous study.
  • Fast-tracking = completing things simultaneously
  • Crashing a critical path means shortening the time allotted to a critical task.
  • A task with no slack is known as a critical path activity.

How To Develop a PERT Chart?

Step 1: Make a List of Milestones and Tasks for Your Project

Milestones, also known as deliverables, are similar to checkpoints in a racing video game, and each turn, pass, or straightaway you drive is a task you accomplish to reach those checkpoints.

Step 2: Determine the Order in Which Those Tasks Should Be Completed

Now that you’ve listed all the milestones and charges required to complete your project, it’s time to put them in a proper order for completion.

Make sure to mention any task dependencies while establishing this sequence and order of tasks.

Step 3: Establish Time Constraints for Your Tasks

This is the most technical stage in creating a PERT diagram.

Step 4: Create Your PERTChart

You can make a PERT chart by sketching one or using PERT software.

The visual design of a PERT chart is not limited to the samples provided above. PERT is more of a function than a visual style of project structure representation.

Make your PERT chart in whatever way that makes sense to you, but make sure to incorporate all of the information you acquired in the previous steps.

Step 5: Create a Critical Path Diagram

You may use your PERT chart to identify the critical route of your project now that you’ve filled it in with all of the necessary information. Your critical path is identifying the most significant steps that will assist you in establishing the project’s minimum duration.

Step 6: Make Any Necessary Changes to Your PERT Chart

Your PERT chart is a flexible planning tool that you can adjust. This diagram might be updated during the project execution phase as circumstances change.

Use your PERT chart as a starting point for your project, and then transfer it to a Gantt chart for oversight and management.

Gantt Charts

Origin of Gantt chart

In the mid-1890s, Karol Adamiecki invented a diagram that he later dubbed a “harmonogram.” (akin to a Gantt Chart). 

Adamiecki’s writings were published in Polish and Russian. 

In the English-speaking world, these languages were less well-known. This limited their acceptance and acknowledgment of his authorship.

In the interim, Henry Laurence Gantt, an American engineer and consultant, popularised a similar concept in the west (publishing articles on it in 1910 and 1915). 

As a result, Henry Gantt is regarded as the inventor of the Gantt Chart (hence the name).

Earlier, teams used to create the Gantt charts using hand. Therefore when the project changed, they had to redraw them. 

Personal computers facilitated the construction of complex Gantt charts starting in the 1980s. Meanwhile, they solved one of the most serious issues: the constant modifications that required redrawing the chart each time.

Online Gantt Charts are becoming a standard part of project management tools and software.


The name “Gantt” is rare, and numerous misspelled alternatives exist. 

As a result, Henry Laurence Gantt’s (1861-1919) most well-known management legacy was the ‘Gantt Chart.’ 

It is now widely used as a project management tool, although it was a groundbreaking innovation in the 1920s.


  • Tasklist: A list of project tasks that runs vertically down the left side of the chart, and you can further arrange it into groups and subgroups.
  • Months, weeks, days, and years are displayed horizontally at the top of the Gantt chart.
  • On the Gantt chart, a dateline is a vertical line that highlights the current date.
  • Bars: Represent the tasks by flat markers on the right side of the Gantt chart that show progress, duration, and the start and end dates.
  • Milestones are yellow diamonds that mark important dates, decisions, and deadlines.
  • Dependencies: Light grey lines connecting actions that teams must complete in a specific order.
  • Progress: Indicates how far along a project is by using percent complete and bar shading.
  • The person or team in charge of executing a task is known as the resource assigned.

Steps To Develop a Gantt Chart

Step 1: Go Over the Scope Baseline

Gather the team and review the scope baseline, which comprises three parts: The Work Breakdown Structure (WBS) Dictionary, the Scope Statement, and the Work Breakdown Structure (WBS). 

A project team member should ensure that the scope baseline covers the project scope.

Step 2: Develop Activities

The project team breaks down each WBS work package into activities using decomposition. 

The team must establish guidelines for constructing schedule activities, much as they did when creating WBS work packages. 

The final timetable should be the most effective and efficient possible, and too many activities might be just as harmful as not enough.

Step 3: Arrange the Activities

Each activity has a connection to at least one other activity. Every action, except the first and last, has a precursor and a successor. 

When you sequence activities, you put them in the appropriate order and employ the right relationships.

Step 4: Calculate Your Resources

Resources must be recognized and estimated before you determine the duration. Labor, materials, and equipment are all resources. 

Analogous, Parametric, Three-Point, and Bottom-Up are some estimation methodologies employed. 

The basis of the estimate should take into account skills, abilities, and technology. 

After calculating the resources, teams can assign them to the activities on the timetable. 

A resource calendar also shows when and where resources are needed.

Step 5: Calculate Timeframes

The period between the start and finish of action is known as duration. 

Examine the available resources, their relationships, and the order in which teams must complete them. After that, estimate the length of each task.

Step 6: Make a Schedule

Load the data into a project management software program to create the Gantt chart. 

Examine the timetable to confirm that teams have addressed all hazards to the schedule. Make sure that response strategies and scheduling contingencies are incorporated. 

Adding Buffers at the activity, project, or levels is common to address schedule contingencies. 

A buffer is an operation with no resources or scope but is used to offer extra time and mitigate scheduling concerns. 

Resource optimization techniques such as resource smoothing or leveling are applied to produce realistic schedules. 

Examine and accept the plan. The schedule baseline is the approved Gantt chart schedule.

What’s the Difference Between PERT and Gantt Charts?

The above is a reasonable question given the structural similarities between Gantt charts and PERT charts. 

Gantt charts and PERT charts highlight project tasks and task dependencies and assist you in determining your critical path.

PERT charts are displayed as a network diagram that depicts the order of tasks, whereas Gantt charts are presented as a horizontal bar graph. 

The most significant distinction between the two is when they are employed.

The two charts convey project data, that is the most significant variation between them.

A Gantt chart, also referred to as a bar chart, shows project activities and timelines in a logical order. 

Individual tasks are represented on the y-axis, while you’ll see time represented on the x-axis. 

PMs can alter activities in the chart as the project proceeds to keep it on track for a timely delivery. This helps to improve efficiency and optimize time management.

On the other hand, a PERT chart is a flow chart or network diagram. It shows all project activities in individual boxes and connects them with arrows to highlight task dependencies. 

Although PERT charts do not feature dates along their x-axis like Gantt charts, the separate packages that make up PERT charts define the time required to accomplish each activity.

You can create a project timeline using the PERT chart after identifying tasks. 

While a project is in process, teams use Gantt charts to track the status of each job and split tasks down into smaller chunks.

Which Is Better for Me: PERT or Gantt?

Gantt and PERT charts each have a place in the project manager’s toolset because of the different ways they visually depict project tasks and life cycles. 

It is easy to create and modify both charts to help you maximize planning and time management throughout the project cycle.

But you’ll only have time to implement one of these. 

Gantt charts may be appropriate for teams new to specific tasks, whereas PERT charts may be best for groups familiar with the route ahead.

The PERT and Gantt chart binary is a common misunderstanding. 

You may simply figure out your basic workflow with a PERT chart and add it to your project management software like a Gantt chart. 

You can use both because PERT charts are better for planning and Gantt charts are better for execution.


A PERT chart is frequently favored over a Gantt chart because it depicts task interdependence (another popular project management charting). 

While the PERT chart, especially for large-scale projects, can be challenging to comprehend, project managers frequently employ both strategies to accomplish numerous goals.

On the other hand, a Gantt chart fails to illustrate explicit dependencies or linkages between tasks and enough information to show the critical route and detailed information for each activity.

Crafting great product requires great tools. Try Chisel today, it's free forever.