CODEWITHSUNDEEP
umlactivity-diagram
Carlos
Carlos

Reputation: 1562

Data flow vs Object flow in UML activity diagram

In UML Activity diagram there are Data flow , Object flow and control flow.

I can't get the differences between Data flow and Object flow?

Upvotes: 1

Views: 2640

Answers (2)

Vladimir
Vladimir

Reputation: 2119

There is no data flow in activity diagrams. Object flow plays the role of data flow as well. Activity object flow defines how and when objects(data) are transferred from one node to another to be processed.

See further details in the UML specification document, part ObjectFlow. UML specification is a free document and can be downloaded from www.omg.org.

Upvotes: 1

Gangnus
Gangnus

Reputation: 24464

Both Control Flow and Data Flow diagrams appeared in far 50-ties. They were cool in times of Structured programming. Object-oriented data flow diagrams appeared later, with Object Oriented Programming. It is the adaptation of the former two to the new conceptions. Also appeared a shortened name, Object Flow Diagram.

It has really two meanings. The flow of objects among other objects and/or components, and the flow of data among objects. The Object flow diagram in the first meaning now is wholly supported by the Components diagram and has no sense by itself. If you make Components diagram, and have modeled the messages between components over the class, up to the object level, such Components diagram could be named an Object Flow diagram.

The other variant could have some use only when you have already very deeply modeled structure, so that you know objects, and you are planning how these objects will send other objects between themselves. These diagrams now will be rather realized as Object diagrams, Composite Structure diagrams and their hybrids.

Both uses are useful, but not so frequent.

As for the Control Flow diagrams, object oriented or not, Sequence/activity/state diagrams are used instead now.

On the other hand, the old good Data Flow diagrams are still very useful. When you are planning the inner processes of the system on the most common level, while concertizing the components, but leaving the data yet in the human language, these DFD are very convenient.

Upvotes: 2

Related Questions