Close

The Ultimate Guide to PERT Charts

トピック一覧

Ever feel overwhelmed by the complexities of managing a project? Juggling tasks, deadlines, and dependencies can quickly turn even the most well-defined project into a tangled mess. The good news is that there are tools and techniques that bring order to the chaos and organize a complex project scope into a cohesive project roadmap.

A PERT chart, or program evaluation and review technique chart, is a powerful project management tool that helps visualize project schedules and identify critical paths. PERT charts apply a PERT formula, which calculates a realistic expected timeframe for a task to help projects stay on schedule, on time, and on budget. In general, PERT charts can decode complex projects and help set teams up for successful project completion.

This comprehensive guide reviews PERT charts and their use for successful project planning and execution. It also explores the core principles behind PERT charts, reviews the step-by-step process of creating one, and explains how to use them to optimize project timelines, resource allocation, and team productivity.

What is a PERT chart?

PERT charts are a type of visual aid used in project management. Created for the U.S. Navy during the Cold War, PERT charts are effective tools for planning and arranging projects of all shapes, sizes, and complexities. Fundamentally, a PERT diagram aids project managers in estimating the amount of time necessary to finish a project by considering the duration of each task and its interdependencies.

PERT charts are aesthetically pleasing because they concisely convey intricate project structures through visual aids. They map the order of tasks and highlight the connections between them using a network of arrows and nodes.

With the help of this visual representation, project managers can identify critical paths—the longest chain of interdependent tasks that ultimately determine the total project duration. Managers can ensure timely project completion by concentrating their resources on optimizing these essential components and identifying these critical paths.

PERT charts vs. Gantt charts

PERT charts and Gantt charts are valuable project management tools that play distinct but complementary roles. PERT charts excel at visualizing task dependencies and estimating project timelines based on critical paths. They depict the project as a network, where arrows represent tasks and nodes signify milestones or task completion points. The emphasis lies in understanding how tasks are interrelated and how delays in one task can impact subsequent tasks.

Gantt charts, on the other hand, focus on scheduling tasks over time. Imagine a bar chart that lists tasks along the vertical axis and time across the horizontal axis. A bar that stretches across the timeframe represents each task and signifies the projected completion time. This visual representation makes it easy for project managers to identify task durations, overlaps, and potential scheduling conflicts.

In essence, PERT charts provide a high-level overview of the project's flow and critical path, while Gantt charts offer a more granular view of the project schedule day by day. By leveraging these tools, project managers gain a comprehensive understanding of their projects, considering the task dependencies and the specific timeframes allocated to each activity.

How does a PERT chart work?

The core components of a PERT chart are tasks, dependencies, and the critical path. Tasks represent the individual activities teams must complete within a project. The chart depicts these tasks as boxes or circles within the chart. Dependencies illustrate the relationships between tasks, highlighting which tasks require completion before others can begin. Arrows link these dependent tasks, showcasing the project’s sequential flow.

The critical path is the heart of a PERT chart. It represents the longest sequence of dependent tasks within the project. Identifying the critical path is crucial because it dictates the minimum time necessary to complete the project. There can be multiple paths through a PERT chart, but the critical path has the longest overall duration. Delays in any task along the critical path will directly impact the project deadline.

Imagine a construction project. The building’s foundation (task A) must be completed before framing the walls (task B) can begin. Similarly, the walls must be up before installing the roof (task C). In this scenario, tasks A, B, and C would form the critical path, as they are all dependent on each other. Their combined duration determines the minimum time to complete the building structure.

By visualizing these dependencies and pinpointing the critical path, PERT charts empower project managers to proactively identify potential bottlenecks and allocate resources strategically to ensure timely completion.

When to use a PERT chart

PERT charts offer significant advantages in specific project scenarios:

  • Complex projects: When managing projects with numerous interconnected tasks and dependencies, PERT charts excel at visually untangling the web of activities. They clearly convey how tasks flow and how delays in one area can cascade through the project.
  • Time-sensitive projects: PERT charts are ideal for projects with strict deadlines. By identifying the critical path, project managers can focus on optimizing these core tasks and mitigating potential risks that could threaten timely completion.
  • Uncertain projects: PERT charts can be invaluable for projects with inherent uncertainties, such as those involving new technologies or external dependencies. The ability to account for estimated task durations with optimistic, most likely, and pessimistic scenarios allows flexibility and helps create realistic project timelines.

PERT chart advantages

PERT charts offer several advantages that make them valuable tools for project management:

  • Visual clarity: PERT charts provide a clear and concise visual representation of project tasks and their dependencies. This visual approach makes understanding the overall project flow, identifying potential bottlenecks, and communicating project plans to stakeholders easier.
  • Improved planning: PERT charts enable better project planning by highlighting critical paths and task dependencies. Project managers can allocate resources more effectively, focusing on tasks impacting the project timeline significantly. This focus on critical paths helps ensure timely project completion.
  • Flexibility: PERT charts can accommodate the uncertainty inherent in many projects. The ability to factor in optimistic, most likely, and pessimistic estimates for task durations enables the creation of more realistic project timelines. This flexibility is crucial for adapting plans as the project progresses and unforeseen challenges arise.

PERT chart disadvantages

While PERT charts offer valuable benefits, there are also some limitations to consider:

  • Complexity for large projects: PERT charts can become quite complex to create and maintain for projects with multiple tasks and intricate dependencies. The visual representation can become cluttered, making it challenging to decipher task relationships and identify critical paths.
  • Time commitment: Creating a PERT chart requires a detailed analysis of project tasks and time estimations for each activity. This process can be time-consuming, especially for larger projects. Gathering accurate time estimates might involve consulting with team members and considering historical data from similar projects.

How to make a PERT chart

Now that you know what PERT charts are and understand their core concepts, this section will review the practical steps to creating one, outlining the whole process from identifying tasks to monitoring progress.

Identify tasks

Break the project down. The first step is to list all the individual tasks involved in the project. This comprehensive list is crucial, as it forms the foundation of the PERT chart.

Establish dependencies

Untangle the web. Once the task list is created, analyze the relationships between each task. Identify which tasks require completion before others can begin. This process will result in a flowchart that visualizes the dependency requirements and adjusts the overall project plan as various parts are completed. Remember that these dependencies are crucial for understanding the project flow and pinpointing potential bottlenecks.

Connect your chart

Visualize the journey. With tasks and dependencies defined, it's time to build a visual representation of the project. Various PERT charting tools are available, or you can create one manually using software such as Microsoft Visio or even a whiteboard.

Determine project timelines

Time it out. After establishing tasks and dependency relationships, determine the key check-in points and the overall deadline and plot the project and resource allocations accordingly.

Oversee task progress

See it through. Once you map everything out, use the chart to monitor overall progress. The PERT chart will help oversee task progress, track whether tasks are on schedule, identify any roadblocks, and enable the team to adjust as needed to keep projects on track.

Ready to make a PERT chart? Get started with Confluence whiteboards

Confluence whiteboards enable teams to effortlessly capture and organize ideas during the brainstorming and early planning stages. They provide a freeform surface to document these ideas before moving them into a more structured format, such as a page or a team's backlog. With close integration with Jira and organization through Kanban boards, you can seamlessly transform your “unstructured” thoughts into actionable plans within Jira. Confluence whiteboards streamline and connect essential functions from brainstorming to execution, fostering a more consolidated and connected approach to project management.

PERT charts offer a valuable visual tool for project managers to navigate complexities. Understanding task dependencies and identifying critical paths empowers optimal project schedules, effectively allocating resources and ensuring timely completion.

Consider Confluence as the central hub for PERT chart creation and project collaboration. Confluence whiteboards provide a flexible and visual workspace to map out project tasks, establish dependencies, and share the PERT chart within teams. These whiteboards go beyond simply creating a PERT chart; they bridge the gap between brainstorming and action. Make a PERT chart in Confluence whiteboards today.

以下も参照してください

プロジェクトポスターのテンプレート

プロジェクトチームと関係者の連携に役立つ 1 ページのコラボレーション資料です。

プロジェクト計画テンプレート

次のプロジェクトに向けたマイルストーンの定義、スコープ、計画を設定します。

Confluence で、すべてのチームのコンテンツ コラボレーションがより迅速になります

次の記事
Project deliverables