{"id":57288,"date":"2024-08-12T12:00:00","date_gmt":"2024-08-12T17:00:00","guid":{"rendered":"https:\/\/www.projectmanager.com\/?p=57288"},"modified":"2026-04-28T14:19:27","modified_gmt":"2026-04-28T19:19:27","slug":"precedence-diagramming-method","status":"publish","type":"post","link":"https:\/\/www.projectmanager.com\/blog\/precedence-diagramming-method","title":{"rendered":"An Intro to the Precedence Diagramming Method (PDM)"},"content":{"rendered":"

Scheduling a project can be daunting. Fortunately, there are tools and techniques such as the precedence diagramming method to help organize activities and get them all done on time.<\/p>\n

Precedence diagrams are used to visualize the tasks in a project from start to finish. If you\u2019re not familiar with the precedence diagramming method, you\u2019ve come to the right place. Let\u2019s take a close look at this technique and how it assists project managers when scheduling their projects.<\/p>\n

What Is the Precedence Diagramming Method (PDM)?<\/h2>\n

The precedence diagramming method is a project planning technique that allows project managers to map out all the tasks in a project to plan the order in which they will be executed. This is done by using precedence diagrams, which are project network diagrams that show tasks, their duration and dependencies.<\/p>\n

The precedence diagramming method (PDM) is similar to the program evaluation and review technique<\/a> (PERT), activity-on-node diagramming and the critical path method (CPM), because those techniques also use project network diagrams, but each has its key differences.<\/p>\n

What Is a Precedence Diagram?<\/h2>\n

A precedence diagram is a project management chart that represents project tasks and shows their durations and the task dependencies between them. Precedence diagrams consist of nodes, which represent tasks, and arrows that connect them to show the task dependencies so they can also be referred to as activity-on-node or AON diagrams.<\/p>\n

However, precedence diagrams can be labor-intensive and time-consuming. You\u2019ll need to manually adjust them every time changes are made to your project plan.<\/p>\n

With robust project management software such as ProjectManager<\/a>, you can create Gantt charts, a much more powerful alternative to precedence diagrams. Our online Gantt charts allow you to assign tasks, set task dependencies, identify the critical path and much more with just one click.<\/p>\n

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ProjectManager\u2019s Gantt charts are the perfect complement to precedence diagrams. Learn more<\/a><\/figcaption><\/figure>\n

Now that we\u2019ve defined what precedence diagrams are, let\u2019s see how task dependencies work in the PDM.<\/p>\n

What Are the Four Types of Precedence Diagramming Dependencies?<\/h2>\n

The precedence diagramming method uses the four types of task dependencies commonly used in project management<\/a>. However, when implemented with PDM, these task dependencies are also called precedence relationships or PDM relationships.<\/p>\n