What Is a PERT Chart? Meaning, Diagram, Template

Need help with mapping project works? A PERT chart, also known as a PERT diagram, is an excellent solution for tracking dependencies. Let us learn more about the PERT chart meaning, its diagram and how PERT helps in effective project management. 

A Brief Introduction to PERT Chart

Before discussing the PERT chart meaning, let’s understand the full form of PERT. PERT stands for Programme Evaluation and Review Technique. 

The PERT chart is a visual project management tool that helps map out and track project tasks and timelines, assisting Project Managers in creating project schedules conveniently. The graphical representation of the project timeline helps Project Managers break down tasks in the project for analysis. 

A PERT diagram‘s breakdown structure helps organise a complex project containing various moving parts by visualising the dependencies in every step of the process. The chart also helps in the project’s risk assessment. 

Using a PERT chart in project management guides the Project Manager and the team to complete the project on time with minimal doubts and wastage. The outcome is better results for the working team and customers alike. 

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Difference Between a Pert Chart and Gantt Chart

Gantt charts and PERT charts are project management tools, but their purposes differ. Let us take a look at the differences:

Gantt Chart

• Primarily used for monitoring a project’s progress, they ensure the tasks are completed on time. 
• Helps Project Managers visualise task progress within a period 
• Emphasise the span of tasks with their start and end dates 

PERT Chart

• Helpful in scheduling and planning projects with multiple tasks and dependencies 
• Helps visualise task dependencies and their interrelation in a project 
• Helps emphasise the timing and sequence of tasks in a project

 Gantt charts mainly focus on job progress over time, while PERT charts deal with relationships between tasks. 

What Is the Best Time for Using a PERT Chart?

The PERT diagram is best used during the planning phase of a project. With the chart, you can determine the project’s critical path, calculate the time for starting and finishing tasks, and prioritise your tasks while creating the project schedule. 

A PERT chart represents the tasks in the project which are dependent on other tasks. Thus a Project Manager can avert delays with advanced planning so that the dependent tasks are finished on time without hampering project progress. 

Also, during project planning, a manager should have an almost accurate idea of the project duration for resource scheduling. A PERT diagram represents the estimated time required for the project completion and is particularly beneficial for large and complex projects. 

Using PERT in Project Management

Directional arrows and nodes make up a PERT chart. You can check a PERT chart example to understand the representation.

The nodes are numbered circles or boxes representing a milestone in the project. The arrows represent activities/tasks to be completed before moving to the next milestone/event. 

A Project Manager visualises the tasks and dependencies of the project via the PERT chart, chalking out the ‘high-priority’ tasks for successful project completion and delivery. 

Terminologies and Concepts Used in a PERT Chart

Here is a comprehensive list of the various terminologies used in a PERT chart:

• Arrows 

They visually represent the various tasks and activities occurring throughout the project. The arrow’s direction is indicative of the task’s sequence. Diverging arrows represent different tasks that can be completed simultaneously. 

• Nodes

Nodes are also visual representations of events or milestones within the project. They are depicted as numbered circles or numbered boxes. 

• PERT Event

The point in the project when one or more tasks begin or get completed. 

• Fast Tracking

It is the time in the project when activities and tasks are performed simultaneously. 

• Critical Path

It is the most time-consuming or the longest path from the beginning to the end of a task or an event. 

• Expected Time

It is the most accurate estimate of the time taken for a task to be completed, considering any obstacles or problems that might come up. 

• Lag Time

It is the earliest point at which one task can follow the other. 

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Example of a PERT Chart 

Let us take a look at this PERT chart template example:

PERT chart template

This PERT chart template displays an intricate workflow with a multi-step website launch process. Even the arrow is time-stamped by a week to understand the tasks that will take place in the project. Many tasks and subtasks go into making this project a success. 

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Making a PERT Chart

Follow these simple steps to create a PERT chart, including the PERT diagram:

1. Analyse the project scope

Before you begin, understand and break down the scope of the project. Identify the milestones and the individual tasks needed to achieve the milestones. Following this configure the sequence or order of the tasks and the various dependencies. 

To create the PERT chart, you will need a list of tasks, their dependencies and the milestones. 

2. Creating the PERT chart

Start your PERT diagram once you have all the information needed to create a PERT chart. Sequence your tasks in the correct order and estimate the time required to complete each task successfully. 

3. Determining the project duration

Now that your PERT diagram has the task details, you can create a project schedule by adding estimated periods for all the tasks. If drawing the chart manually, you can use the PERT chart formula to estimate the project duration. 

4. Identify the critical path and slack

Your PERT chart has tasks, durations, and deadlines. You can calculate the critical path and even identify chances of slack. With the progress of the project, make sure to come back and revise this project management document chart from time to time. 

Conducting a PERT Analysis 

Conducting a PERT analysis is crucial as it helps determine the project’s chances of completion within the stipulated timeframe. To conduct a PERT analysis, use standard deviation for determining the deviation volume in the data.

For calculating standard deviation, you can use the formula: (P-O) / 6, where P stands for the most pessimistic estimate, and O stands for the most optimistic estimate for the project’s length. 

A lower standard deviation indicates that you can confidently meet your expected project completion date. 

PERT Chart Software

Many Project Managers prefer software to create their project’s PERT diagram rather than manually creating one. With a basic outline in place regarding the project plan, the software can continue from there. 

You can choose from different PERT chart templates on various websites and start chart creation quickly. Some of the most popular PERT chart generators are:

• Visme
• Creately
• Cacoo
• SmartDraw
• Lucidchart
• Miro
• Adobe Express

Along with the availability of countless templates, you can also customise the PERT diagram per your needs using various software for PERT chart creation. 

Benefits of PERT Chart Use

Some of the most prominent advantages of using PERT in project management are as follows:

• Helps simplify complex projects

Using a PERT chart enables Project Managers to handle complex projects efficiently. The PERT diagram provides a precise estimate of the time needed to schedule the project and the volume of the resources required for project completion.

With the breakdown structure and the nature of the PERT chart, Project Managers can ascertain the complexity of a project. It also covers the dependencies between every step in the process. 

• Helps in exploring the hypothetical

While handling a project, unexpected events might crop up. With a PERT chart, Project Managers can create various what-if scenarios, preparing them for unexpected situations. 

While mapping out resources, tasks and time for a project, the Project Manager can develop a quick idea of what will work and what might fail in the project. This can save valuable time, which would otherwise be wasted in making unnecessary revisions. This flexibility is of great help in project management. 

• Helps in collaborating with different departments and subject matter experts in a project

Different departments of an organisation are involved in a project. As a PERT chart is a project management tool, it collects relevant data from all departments involved in the project. Project Managers can identify job roles and endow responsibilities for those tasks. 

This leads to strong communication and collaboration between different departments, better aligning the organisation’s strategic goals. 

• Helps in better risk management

With the creation of PERT diagrams, Project Managers can identify potential risk areas in a project. This allows a deep analysis of risk factors and helps develop suitable mitigation strategies for the project. 

Better risk management helps in smooth progress and successful completion of the project. 

• Helps in better resource allocation for a project

The success of a project depends significantly on resource allocation. A Project Manager’s job is to identify the best resources for a particular project. Once identified, the resources must be allocated effectively so that no one is overburdened with work. 

Effective resource allocation ensures minimal risk of delays in project submission and delivery. 

• Easy visibility and better analysis of the critical path

Project Managers are well aware of the importance of the critical path in a project. For streamlining this aspect, Project Managers often rely on PERT charts. Analysing the chart provides a clear understanding of slack values. This would help prevent the risks that would delay project submission otherwise. 

Downsides of PERT Chart Use

Like the benefits or advantages, PERT charts come with their share of disadvantages. Some notable disadvantages are as follows:

• Time-consuming

Creating a PERT chart is quite time-consuming. Moreover, a lot of effort goes into the making of these charts. 

• Not easily comprehensible

PERT charts are quite complex. People who do not have any project management experience or exposure might find deciphering PERT diagrams challenging. 

• Limited flexibility

Making amendments and changes to the project plan is difficult once you create a PERT chart. Therefore you have limited ability to respond to any change in project needs. 

Conclusion

The PERT chart has been used since its creation in 1957 and plays a significant role in project management. Emerging Project Managers must thoroughly understand its use, advantages and disadvantages to use it for timely project completion successfully.

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