What is the Differences between Sequence Diagrams and System Sequence Diagrams?
System Sequence Diagram (SSD) vs Design Sequence Diagram
Sequence Diagram: It shows interaction between two objects. System Sequence Diagram: It shows interaction between system & actors.
A System sequence diagram visualizes a use case, while a sequence diagram visualizes a method of a class.
The elements participating (exchanging messages) in a system sequence diagram are Actors and Systems. The messages exchanged by these elements could be any type depending on the systems (from web service calls to data input from a human).
The elements participating in a sequence diagram are objects (instances of various classes). The messages exchanged by these elements are method invocations.
First you would analyse and document the use cases. Each use case describes a main business task required. The system use case diagram is part of this activity.
Later you come to design each subsystem, namely each element participating in the system use case diagram. You draw one or more class diagrams depicting the classes participating to the solution. Then you would draw a sequence diagram for the most important (or difficult to understand) methods.
Differences between Sequence Diagrams and System Sequence Diagrams
The Difference between a system sequence diagram and a sequence diagram
A Sequence Diagram facilitates understanding of the interactions between humans and systems by the system designer, implementer, and user. It is often referred to as the System Sequence Diagram. A series Diagram depicts the series of interactions between the various actors. It aids in determining the chronology of interactions between the actors involved.
A System Sequence Diagram (SSD) depicts a use case, whereas a sequence diagram depicts a class method. Participants in a system sequence diagram are referred to as “actors and systems,” whereas participants in a sequence diagram are referred to as “objects.”Click here to know the difference between Domain Class Diagrams and Design Class Diagrams.