PERT analysis is one of the most used techniques in project management. Today we discuss how to do a PERT analysis and what are its pros and cons.
Project management is a complex task, so people involved in project management use multiple tools and techniques to make their tasks easy.
Do you know what is one of the techniques that are used in project management the most? Did you say PERT Analysis? Well, yes, it is one of the most used techniques in project management.
While working on any project, project managers first calculate the estimated project time. To calculate it accurately, project managers use PERT analysis.
With the help of this analysis, managers list every small task to be completed for the completion of the project and associate time with them. In this way, managers can make realistic projections about the completion of any project.
Since PERT analysis is one of the most used techniques in project management, let's discuss what PERT analysis is in detail.
What Is PERT In Project Management?
PERT is an acronym for Program Evaluation and Review Technique. It is a project management technique used to analyze and represent the tasks and activities required to complete a project.
The United States Navy originally developed the PERT technique in the 1950s to manage complex projects like developing Polaris missiles.
The PERT method is based on a graphical representation of a project's tasks and the time required to complete them. The technique involves breaking down a project into individual tasks or activities and then identifying their dependencies.
This information creates a network diagram illustrating the tasks' sequence and interdependencies.
The PERT diagram includes nodes representing the tasks and arrows representing the dependencies between them.
Each node is assigned an estimated time for completion, and the diagram calculates the project's expected duration.
PERT also incorporates a technique called "critical path analysis" to identify the tasks that are critical to the project's timeline and must be completed on time to ensure the project's success.
PERT can be useful for project managers because it helps them identify the critical path of a project, estimate project completion time, and identify the tasks most likely to cause delays.
This information can help managers allocate resources, identify potential bottlenecks, and decide how to optimize the project schedule.
How To Do PERT Analysis On A Project?
Before starting any project, it is very important for project managers to conduct a PERT analysis. To do that, several steps are to be taken.
Identify The Tasks And Activities Required To Complete The Project
Identifying the tasks and activities required to complete a project is a critical first step in PERT analysis. Project managers often use a work breakdown structure (WBS) technique to do this.
A work breakdown structure is a hierarchical project decomposition into smaller, more manageable tasks. It starts with the project and breaks it down into smaller deliverables, further into tasks and sub-tasks. The end result is a detailed list of all the tasks and activities required to complete the project.
For example, suppose constructing a tall commercial building is a project. In that case, several other activities are to be done to complete this task, such as purchasing land where the building will be built.
Besides that, getting the architectural design of the building ready is another task to be completed before starting the project. Moreover, hiring the workforce for the execution of the project is also necessary.
Determine The Sequence And Dependencies of Tasks
After identifying all the tasks and activities required to complete the project through the WBS, the next step in PERT analysis is to determine the sequence and dependencies of the tasks. This involves identifying which tasks must be completed before others can begin and which can be completed in parallel.
There are three types of task dependencies. The first dependency is Finish-to-Start. It means a task can start once a previous task has been completed. For example, the construction phase of the building can start once the design phase has been completed.
Another task dependency is Start-to-Start. According to this dependency, two tasks can start simultaneously, but one must start before the other.
For example, the design team and HR team might be working on different aspects of a project, but the design team must start first to provide the HR team with the necessary information on how much staff to employ.
The third type of task dependency is Finish-to-Finish. This means that two tasks can only finish once both are completed. For example, design and HR teams might be working on different aspects of a project, but both teams must finish their work before the project can move to the next phase.
Estimate The Time Required For Each Task
To perform a PERT analysis on a project, estimating the time required for each task is essential. This involves using historical data, expert opinions, or other methods to estimate the duration of each task.
Using historical data can help in how long similar tasks have taken in the past. This information can be gathered from previous projects, internal data, or industry benchmarks. In addition, expert opinions can be gathered from team members who have experience with similar tasks or projects.
For example, in the case of constructing a building, one month is associated with getting the design of the building ready, and two months are given to the HR team to employ the required team.
Create The PERT Diagram
After time estimates have been determined, project managers can create the PERT diagram by drawing a network of arrows representing the tasks and their dependencies. A node or a box represents each task, and the arrows show the sequence of tasks and their dependencies. In addition, the arrows are labeled with the estimated duration of the task.
By creating a PERT diagram, project managers can visualize the project plan and understand the relationships between tasks. This helps them to identify potential bottlenecks or areas of risk and make informed decisions about resource allocation, scheduling, and budgeting.
The PERT diagram can also communicate the project plan to stakeholders and team members and ensure everyone is working towards the same goals.
Calculate The Critical Path
Calculating the critical path is an essential step in PERT analysis. It helps project managers identify the sequence of tasks that will take the maximum time to complete and determine the project's minimum completion time.
Project managers can use the PERT diagram created earlier to calculate the critical path, which shows the dependencies between tasks and their estimated durations. The critical path can be determined by identifying the tasks with no slack time or float and arranging them to create the sequence of critical tasks.
Once the critical path has been identified, project managers can use this information to make informed decisions about resource allocation, scheduling, and budgeting. They can also use the critical path to monitor the project's progress and ensure it is on track to meet its goals.
Analyze The Results
This step involves using the information obtained from the PERT diagram to identify potential bottlenecks or areas of risk in the project plan and making necessary adjustments to the plan to ensure project success.
By using the PERT diagram, project managers can identify critical tasks with no slack time or float, and determine which tasks will likely take the longest to complete. They can also identify areas where resources may be over or under-allocated and where delays may occur due to dependencies or other factors.
Monitor Progress
Monitoring the progress of a project is a critical aspect of project management. It involves tracking the project's actual performance against the planned performance to identify deviations or variances.
This information is then used to update the PERT diagram and adjust estimates to ensure the project stays on track. As the project progresses, project managers should regularly review its status and compare it to the original plan.
This includes monitoring the completion of tasks, identifying any delays or changes in scope, and tracking resource utilization and costs.
What Is The PERT Formula?
The PERT formula is a mathematical formula used in PERT analysis to calculate the expected duration of a project or task. The formula is:
Expected duration = (optimistic time + 4 x most likely time + pessimistic time) / 6
In this formula, the optimistic time is the shortest possible time that a task could take to complete, the pessimistic time is the longest possible time that a task could take to complete, and the most likely time is the time that a task would take to complete under normal circumstances.
Using this formula, project managers can calculate the expected duration of a task or project. They use this information to create a PERT diagram showing the sequence and dependencies of tasks, along with their estimated durations.
This helps to ensure that the project is completed on time and within budget and that all stakeholders are satisfied with the outcome.
What are the pros and cons of PERT?
Advantages of Using PERT Analysis
Now that you know what PERT analysis is and how to conduct one, let's discuss why you should be using PERT Analysis.
Helps To Identify The Critical Path
PERT analysis allows project managers to identify the critical path and the sequence of tasks that will take the longest to complete and determine the project's minimum completion time.
This information is crucial for project managers to allocate resources effectively and ensure the project is completed on time.
Helps To Estimate Project Duration
PERT analysis allows project managers to estimate the duration of project tasks more accurately. By using three estimates of task duration (optimistic, most likely, and pessimistic), PERT analysis considers the uncertainty and variability inherent in project tasks.
Provides A Visual Representation of The Project
This technique provides a visual representation of the project that is easy to understand and communicate to stakeholders. The network diagram shows the sequence and dependencies of project tasks, which helps to ensure that everyone involved in the project is on the same page and working towards the same goal.
Disadvantages of Using PERT Analysis
While PERT analysis is a powerful tool for project management, this method has several disadvantages.
Time-Consuming
PERT analysis can be time-consuming, especially for large and complex projects. For example, creating the network diagram and estimating task durations can take significant time and effort.
Requires Specialized Knowledge
To conduct PERT analysis, individuals require specialized knowledge and skills. For example, project managers must have a good understanding of project management principles and techniques and knowledge of PERT software tools.
May Be Sensitive To Estimates
PERT analysis relies on estimates of task durations, which may be subjective and sensitive to individual biases. Consequently, small variations in these estimates can significantly impact the critical path and project duration.
PERT Analysis Vs. Critical Path Method
The PERT analysis and the Critical Path Method (CPM) are popular project management techniques that help project managers plan, schedule, and control their projects.
Both techniques help the project managers but differ in specific ways. Following, we have mentioned how these two techniques differ from each other.
Focus
PERT analysis focuses on estimating the duration of project tasks, identifying the critical path, which is the sequence of tasks that will take the longest to complete, and determining the project's minimum completion time.
Whereas CPM focuses on identifying the critical path and determining the earliest possible start and finish times for each task and the latest possible start and finish times.
Approach To Estimating Task Duration
PERT analysis uses three estimates of task duration: optimistic, most likely, and pessimistic, to calculate an expected duration. On the other hand, the Critical Path Method uses one estimate of task duration to calculate the earliest and latest possible start and finish times for each task.
Emphasis On Uncertainty
PERT analysis places more emphasis on uncertainty in project tasks. It considers the probability of each task being completed within its estimated duration. In contrast, CPM assumes that task durations are certain and does not consider the probability of each task being completed within its estimated duration.
How to Draw a PERT Chart Vs. Gantt Chart
The PERT chart and the Gantt chart are commonly used project management tools. However, they have some essential differences that are highlighted below.
Representation
A PERT chart is a network diagram showing the relationships between tasks and the critical path. In contrast, a Gantt chart is a bar chart showing the tasks' start and end dates.
Time Estimates
PERT charts use statistical estimates, such as optimistic, pessimistic, and most likely durations, to calculate the expected duration of each task, while Gantt charts use fixed duration estimates.
Visualization of Dependencies
PERT charts can visualize complex interdependencies among tasks and the critical path. On the other hand, Gantt charts are unable to do that.
Level of Detail
PERT charts are more detailed than Gantt charts and are more commonly used in large, complex projects. In comparison, Gantt charts are helpful for more straightforward and smaller projects.
PERT Analysis: Final Word
PERT analysis is one of the most used techniques in project management. It helps the project managers analyze the time and activities needed to complete a project since PERT analysis breaks down a big project into small tasks and associates time with these tasks.
As a result, project managers become aware of the tasks and time required to complete the project. This article provided a complete overview of PERT analysis by discussing what PERT analysis is and how to carry it out on projects.
After that, this article shed light on the formula of PERT analysis and then discussed the advantages of disadvantages of conducting PERT analysis. At the end of the article, comparisons were drawn between PERT analysis and Critical Path Method along with PERT Chart and Gantt Chart.
