What is the difference between sequence diagram diagram in anaysis phase and sequence diagram diagram design phase?

Question

Could anyone explain me what is the difference between those diagram in each phase. thanks

Answer 1

The analysis model is meant to understand the requirements. Depending on the methodology you’re using, your sequence diagram could represent interaction:

• between domain/business objects
• between analysis classes, that are deduced from the use-cases according to the Entity-Boundary-Control approach.
• sometimes also between actors and the system (even if some purist would say that this is not legit)

The design model means to explain the solution that will be implemented. This means that the sequence diagram would represent interaction between classes that will make your system; not only the domain or business objects, but also internal classes that are specific to your solution (e.g. UI classes, ORM classes, etc.).

You must be aware that depending on your methodology:

• an analysis and a design model may be kept separate, updated and kept in synch;
• only one model may be maintained: an analysis model may be enriched and evolve gradually into a design model
• an analysis model may be maintained until a design model replaces it.

UML is methodology neutral and doesn’t define this.