When designing the process flow of your process, you can start specific flows in the process to handle entity actions events raised by your application.
Whenever an entity record is created or updated with an Entity Action you may use the Conditional Start process activity to start alternative flows to your normal process flow. A typical usage is to handle exceptions to the normal process flow.
When a process is using an entity record that, at some moment in time, is updated in the application and becomes invalid for the process; handle this in your process by adding a Conditional Start to start in the event of updating the entity record, and then design a flow to take an action in the process when the entity record is invalid.
About Conditional Start Tool | Start Conditional Start Action | Entity Actions | About Start Tool | Process Flow Toolbox | Designing Processes