Actions for Campaign Automation 
An action is a planned follow-up activity or task that is designed for reacting to a situation encountered in a business process. Actions can be scheduled, started (manually or automatically), and monitored.
In campaign automation, examples of actions are:
Responding to a marketing campaign
Planning and executing additional campaign steps
Prerequisites
You have defined actions in Customizing for Customer Relationship Management (CRM) by choosing
Marketing 
Marketing and Campaign
Management Campaign Automation
Actions for Campaign Automation 
.You have assigned actions to an action profile in Customizing for CRM by choosing
Basic Functions
Actions Actions in Marketing
Planning Define Action Profiles and Actions
.You have assigned the action profiles to the business transaction types in Customizing for CRM by choosing
Basic
Functions Action in Transaction
Assign Action Profile to the Business Transaction
Type.
Features
Actions are triggered when there is:
An inbound contact or lead object
A customer response is defined as an inbound contact with the object category Business activity. If a preceding campaign element is assigned to this business activity, then rule evaluation starts and additional subsequent steps are scheduled.
NoteThe transaction type used for recording inbound contacts must have an action profile assigned to it. This action profile must be an action profile that is delivered for campaign automation.
End of the note.You can also use a lead object with origin Campaign Response as a customer response. To do this, you need to make sure that the corresponding action profile is assigned to the transaction type.
A campaign reference. This action then triggers the method for inbound processing.
This method checks the campaign process and calls up the next step in the process, it then checks the rules for the next step by going to the decision node and checking these rules.