Software Engineering – The Behavioural Model
March 14, 2010 Leave a comment
this post is the final post of the three main modelling systems in Software Engineering. So far we have seen Class and Functional Modelling; now it’s time to take a look at Behavioural Modelling! 🙂
What is a Behavioural Model?
All behavioural models really do is describe the control structure of a system. This can be things like:
Sequence of operations
and Object interactions
Furthermore, this modelling layer can also be called Dynamic Modelling. The activity of creating a behavioural model is commonly known as behavioural modelling. As well as this, a system should also only have one behavioural model – much like functional modelling.
How do we Represent them?
So, how do we represent behavioural models? Well, we represent them with dynamic diagrams. For example:
(Design) Sequence Diagrams
Communication Diagrams or collaboration diagram
State Diagrams or state machine diagram or state chart
For consistency i will use communication diagram and state diagram 🙂
If we have both a sequence diagram AND and communication diagram, then together these are known as interaction diagrams, this is because they both represent how objects interact with one another using messages.
What do they Describe?
A behavioural model describes when the system is changing.
The key feature (subject) of a behavioural model is – Objects.
Spot the Difference
You’re probably asking your self, what is the difference between a State Diagram, and the Interaction Diagrams: SD’s and Communication Diagrams. Well it isn’t really all that hard to see:
- A State Diagram represents the behaviours of a single object whereas the Interaction Diagrams represent the behaviours of a group of objects that are related.