Architecture Dynamics
What
Sequence diagrams for modelling how objects interact with each other.
How
The dish
Sequence Diagrams modelling more complex dynamics
Ingredients
Process
If you encounter a more complex process during the General Analysis phase which needs some explanation, you can model this process with a sequence diagram when you design the general architecture. You can do this by refining the diagrams from the General Analysis phase covering the relevant details.
How - in details.
General introduction to drawing sequence diagrams
Draw a rectangle at the top of the diagram for each object participating in the process that you want to model. Each rectangle should be labelled with the name of the object and the name of the class separated by a colon � the object name is optional. Now draw a vertical line � the so-called lifeline � below each object.
The first message sent is modelled by a horizontal arrow from the lifeline of the sender to the lifeline of the receiver. The arrow is labelled with the name of the message and the names of the parameters and the return value. The next message sent is modelled by adding a new labelled arrow below the first one. In this way, you can read a sequence diagram from top to bottom.
You can add a condition to the message that must be satisfied for the message to be sent. It is also possible to indicate that a message is iterated by using an asterisk � ?*´.
Optionally, you can illustrate that an object is busy answering a message by so-called activations. Activations are rectangles drawn on the lifelines in the following way:
Why
The sequence diagrams you choose to work on when designing the General Architecture refines the description of the dynamics of the more complicated parts in the system-to-be. To be able to estimate the price for developing the system-to-be, the developer must have a thorough understanding of the more complicated parts of the system.
Example
The level of details of the sequence diagrams produced in General Architecture is typically somewhere between the level of details for the sequence diagrams produced in General Analysis and the sequence diagrams produced in Design.
Used In
The dynamics in the whole architecture is important to keep in mind when doing the detailed implementation.
The dynamic system should perform on a Technical Platform.
