UML diagrams applicable for Background Process

Question

I am trying to create design document for a project which has all background processes in it. The sequence of background processes are as follows:

Process P1->

• Get all records(thousands) from database.
• Analyze validity of records.
• Send valid records to process P2.

Process P2 ->

• Get valid records one by one.
• Do first level processing of data.
• Send this to process P3.

Process P3 ->

• Get records one by one from process P2.
• Based on processing results, update records in database.

I am trying to decide which diagrams to create in this case. Particularly, I am confused about Use Case Diagram. What will be the actor here? Is UseCase diagram even applicable in case of such background processes.

Answer 1

Describing a process is usually done with an activity diagram. If you want to describe a particular execution you should use a sequence diagram.

Answer 2

For a background process a use case isn't applicable I thought? User has no direct interaction with the process, unless you have it interfacing with some trigger that the end user controls.

Activity, Sequence Diagrams and Class Diagrams should be sufficient for your needs.