System modeling of Software Engineering: Design Dynamic Model

This chapter introduces the dynamic model design process, the system instance dynamic model uses the sequence diagram to describe, first introduced chooses the sequence diagram the reason, finally designs each use case main path the sequence diagram separately. The results of this design will enrich and improve the content of the system structure representation service layer, business context service layer, Business rule service layer, Data Transformation service layer and data Access Service layer.

1. Select sequence Diagram

UML provides 4 dynamic models in the form of graphs: Sequence diagrams, collaboration diagrams, State and activity diagrams, and sequence diagrams and collaboration diagrams are interactive graphs. A sequence diagram is a description of how an object interacts, the most important of which is time, which is used in most dynamic modeling because the sequence diagram is related to the use case path. A collaboration diagram is also a description of object delivery, but focus on object space collaboration, collaboration diagram is the "twin brother" sequence diagram, in sequence diagrams and collaboration diagrams can be optional, state diagram only in a class with the dynamic characteristics of replication is useful, more for real-time applications, most applications do not need a statechart diagram. Activity diagrams Describe the sequence of activities that are suitable for form workflows and concurrent processing. Sequence diagrams can clearly describe the implementation steps of a use case path, so it is used most in the system design, and the other 3 graphs are only used when needed, in the case of office automation system, only the sequence diagram can satisfy the need of the design dynamic model. A use case path is described by a sequence diagram, and the sequence of messages from a sequence diagram comes from a class diagram of the object sequences chosen by the use case path.

2. Select sequence Diagram

We take the dispatch process as an example, to explain the sequence diagram design, the new proposed dispatch sequence diagram is as follows:

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