Inline Process is mostly used for readability and usability. It is used to group a set of tasks as an Inline Process. This helps to represent a Process Flow with so many tasks /OFSAA widgets in a systematic and organized way. You can have Inline Process inside another Inline Process.
For example, if an RRF Run definition has multiple sub processes (RRF), each sub process can be represented as an InLine Process.
An Example of Inline Process
Click 
icon. It opens up the process flow diagram of the IFRS_Rating_Classification_Proc as shown:
In this example, IFRS_Rating_Classification_Proc Inline Process has an Inline Process named Rating Reclassification. Double-clicking 
opens up its process flow as shown:
Multiple levels of the Inline Process is supported. You can go to any level by clicking the Inline Process name displayed in the header. Click 
to go to the parent process flow.