Activity modeling emphasizes the sequence and conditions for coordinating lower-level behaviors, rather than which classifiers own those behaviors.

Using activity diagrams for modeling businesses can be complemented by use cases to capture the requirements of the business system. Resources, rules, goals, and actions (workflows) are important aspects to be described in the model.

An activity diagram in the use-case model can be used to capture the activities and actions performed in a use case. It is essentially a flowchart, showing flow of control from one activity or action to another.

The workflow of a use case describes what needs to be done by the system to provide value to the actor. It consists of a sequence of activities and actions that together produce something of value to the actor. The workflow often consists of a basic flow and one or more alternative flows. The structure of the workflow can be described graphically with the help of an activity diagram.