What is The Precedence Diagramming Method

The Ultimate Guide to Understand Precedence Diagramming Method
Precedence Diagramming Method

1. What is Precedence Diagramming Method

A visual depiction of any project/business requires all the existing activities to be visible. One of the approaches for scheduling the activities of a project plan is the precedence diagramming method.

An effective tool for project managers this method helps in constructing a scheduled network diagram for a project plan. This is a method of creating the project network diagram that uses the boxes referred to as nodes representing activities and links using arrows showing dependencies.

Separate boxes or "nodes" are linked with arrows from start to finish to represent a sequential progression of the dependencies between the plan activities. This diagram is often named as the activity-on-node (AON) method too.

1.1 Uses of Precedence Diagramming Method

The precedence diagramming method depicts relationships between activities. Some of its common applications are -

  • This approach is used for constructing the network diagrams for the project schedule like, critical path, critical chain, etc.
  • The precedence diagramming method depicts relationships between activities.
  • It is also an effective resource for stakeholder communication.
  • Set a critical path - define the core functioning of any project or module.
1.2 Benefits Of The Precedence Diagramming Method

This approach offers project managers several advantages:

  • It allows you to find connections between activities and dependencies. By helping you to plan and avoid risks. You can quickly find any scheduled task that is missing.
  • You will identify and focus on critical activities. Thus eliminating delay as critical activities can interrupt the timeline if they are delayed.
  • A network design diagram for a project is a successful means of communication.
  • Stakeholders can access and understand the schedule of activities.
  • You should not develop the project schedule without this diagram to help guide you.
1.3 Relationship in The Precedence Diagramming Method

Four types of relationships between activities are used to accomplish the project's precedence diagramming.


Finish-to-start (FS) relationship - This is the most common form of dependency among activities. If an activity can not start before the predecessor activity ends, then the relationship dependency between the two activities is finish-to-start. For example, the painting of a building can not start in a construction project until the construction is finished.

Start-to-Start (SS) relationship - This kind of dependence shows that two activities can begin concurrently. For example, the design of the screen can start in parallel to database design. In this case, these activities are seen to be start-to-start dependent in the precedence diagramming method.

Finish-to-finish (FF) relationship - This kind of relationship shows that two tasks must be completed together. For example, in a software development project testing & bug-fixing are required to finish together. One cannot finish testing earlier than a bug fix, and bug fixing is said to be finished only when it is verified through testing. This is an example of a finish-to-finish relationship in the precedence diagramming method.

Start-to-finish (SF) relationship - This is a rare form of project activities relationship. Activity B can only finish after the start of Activity A, in this form of relationship. These relationship styles can be used in the just-in-time chain. As an example, you can not vacate your old house until the new house is ready if you are moving to a new home. This example can be plotted as a start-to-finish relationship in a precedence diagramming method.

2. How to How to Draw The Precedence Diagram

Step 1 - Open EdrawMax Online and select a blank canvas to create your diagram using the precedence diagramming method.


Step 2 - Create your diagram, from a wide range of shapes, colors, and grids available.


Step 3 - Add in your text and design your diagram to suit the requirements. You can also icons from the multitude of options available.


Step 4 - Save and export your diagram to any file type you wish to. EdrawMax is compatible with multiple file types like Graphs, PS, PDF, HTML, SVG, Visio.

3. Precedence Diagramming Method Example



This is an example of precedence diagramming method. The A to H represents the activities and the numbers are for defining the core module.

4. Conclusion

A popular and useful method for evaluating and visualizing the logical relationships between activities is the precedence diagramming method.

The results of the precedence diagramming method also serve as a basis for project schedules: finding the critical path, the longest (by way of duration) sequence of activities which defines the minimum project period (source), while sequencing and scheduling activities.

EdrawMax is a conceptual diagramming program that helps construct the flowcharts, hierarchical charts, mind maps, network diagrams, floor plans, and precedence diagramming. The software comes with lots of vector shapes and is easy to customize. You can also connect information, add vectors, and design multiple diagrams at one time.

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