Sequence Activities Process

Posted on March 5, 2009 by


Sequence Activities is one of the 42 project management processes outlined in the fourth edition PMBOK®. It’s categorized as one of the six Time knowledge area processes, and one of the twenty Planning processes.

The purpose of this process is to document the relationships among the project activities. We already have the list of activities—they were documented in the Define Activities process. So the three outputs of the Define Activities process—the Activity List, Activity Attributes, and Milestone List—are all inputs into the Sequence Activities process. For a given activity on the list, we determine which activities come before (called predecessors) and which activities come after (called successors). If one of our activities for baking a birthday cake is “buy ingredients,” then predecessor activities could be to select the recipe and determine which ingredients need to be bought. Successor activities could include preheating the oven, mixing ingredients, and placing the ingredients in a cake pan. The tool and technique of the Precedence Diagramming Method categorizes the relationships between activities based on whether an activity can be merely started, or has to be completely finished, until the next activity can be started or completely finished. For example, you have to finish buying all the ingredients for the birthday cake before you can start mixing all the ingredients together. Another tool and technique of this process is Dependency Determination, meaning that the relationships between activities may be categorized as Mandatory, Discretionary, or External. A Mandatory dependency would be that you must buy the ingredients for the cake before you can possibly place them in a cake pan. An example of a Discretionary dependency is that although it may be best to preheat the oven before mixing the ingredients, you could also mix the ingredients and then preheat the oven. The primary output of Sequence Activities is Project Schedule Network Diagrams, which graphically illustrates the order and relationships among the project activities.