PERT full form is Project Evaluation and Review Technique, a visual tool for project planning. It uses project managers to determine start and completion dates, timetables, and interim tasks. PERT determines the amount of time required to complete a project, task, or activity. It also tracks the project's overall process.
It was first created in 1950 by the US Navy to track their special projects office's Polaris submarine missile program. Sometimes the team does not know the amount of time it takes for the project to be completed, the delegation, and the budget. They can't predict it accurately. Also, the estimates might be pessimistic or optimistic, regardless of whether the project is small or big. But this can be solved by using a PERT chart, which can determine reasonable estimates.
Process of PERT
The following are the steps that need to be followed in the process.
- Create a list of tasks and events needed to complete the project.
- Determine the task sequence.
- Create a chart to represent the steps clearly.
- Calculate the amount of time required for each task.
- Calculate the crucial route that is the longest sequence of tasks in the project.
- Once the project starts, make changes to the chart to reflect the project's progress.
In the PERT chart, events are marked as numbered circles or rectangles, and tasks are marked as straight lines. The sequence needed will be shown by the direction of the arrows and numbers. At every event, the numbers will typically increase by ten. Using this, additional tasks can be added without changing the entire chart.
Implementation of PERT
PERT is depicted using a flowchart. It has four different methods.
- Optimistic time - Calculates the shortest possible time to perform the task.
- Pessimistic time - Calculates the amount of time the task takes in the worst-case scenario.
- Expected time - Calculates how long it will take to complete the task if there are no issues.
- Best time - Calculates the amount of time it takes to finish the task if there are no issues.
Follow the steps below to use the PERT chart.
- List down the important tasks required to execute the project.
- Ensure the tasks are in the appropriate order and also specify how long it takes to complete each task.
- Make a schema diagram of the network.
- Use nodes to represent events and arrows to represent actions.
- Calculate the critical path and the slack if it exists.
Characteristics of PERT
- It acts as a starting point for gathering information and is helpful in decision-making.
- It acts as a foundation for all the planning activities.
- It helps to determine the most efficient resource allocation approach.
- It helps to create proper data reports with the correct format.
- It has a technique called time network analysis.
- It helps the management to identify the necessary so that their project can be completed on time.
Advantages of PERT
- It provides an estimate of the project's completion time.
- It can determine the start and end date of a project.
- It makes a well-organized diagram to display enormous amounts of data.
- The things done during downtime can be identified before the start of the project.
- It helps the project manager determine the important activities for a successful project.
Disadvantages of PERT
- One of PERT's most significant disadvantages is its difficult implementation.
- It is very costly, and maintenance is difficult.
- Though it estimates the projects' completion time, other pathways will become critical if the linked tasks are postponed.
- The estimation of any activity is subjective, which is another significant disadvantage.
- In some cases, the actual and beta distribution will differ, leading to incorrect assumptions.
Frequently Asked Questions (FAQs)
Q1: Why is PERT analysis important?
Ans: It helps the project manager estimate the minimum time required to complete each task. With the help of PERT, the project manager can estimate the minimum amount of time required to complete the entire project.
Q2: List down the three estimates in PERT.
Ans: Optimistic time estimate, a pessimistic time estimate, and a most likely time estimate.
Q3: How can a PERT chart be created?
Ans: Project managers can use Microsoft Excel for PERT chart creation. It has custom software with ready made templates called Lucidchart.