Difference between service-level and system-level Sequence Diagrams? [duplicate]

Question

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Difference between Sequence Diagram (SD) and a System Sequence Diagram (SSD)? (4 answers)

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I have no clue what the difference is between the two Sequence Diagrams. Can anyone enlighten me and help me understand the difference between Service-level and System-level?

Thanks.

Answer 1

Service-level

It is a sort of use case diagram. An SLA is a negotiated agreement between a service requester and a service provider, that can specify levels of functionality, performance, and availability. They look like specific use case diagrams. It is the standard term of IBM. Going in details, we can make a service-level sequence diagram.

System-level

It is not a standard term for diagrams. System analysis is the lowest level of analysis and the result of such are the class diagrams. THEY are on the system level.

Sometimes by this term a component diagram is meant - how your system is composed of subsystems. Here the use of the term has no sense at all. But I have met it in practice, too.

What your client or chief meant by system-level sequence diagram, is a riddle of his own. Let him show how very intelligent he is. Most probably they are sequence diagrams of the lowest level, but better check it.