Software Engineering – Object-Oriented Modelling

So, this is it. This is the post that ties all the previous three together! That is:

1. Class Modelling


2. Functional Modelling


3. Behavioural Modelling

So lets have a look then shall we at Object-Oriented Modelling :)

Identifying a Complete OO System

In order to identify if we have a complete Object-Oriented System Model or not, then we need to look out for this – in other words, do the system satisfy the following equation?

OO System Model = Class Model + Functional Model +  Behavioural Model

Can you Map the Models Together?

A simple answer: yes.

A long winded answer would be this; Say we start off with a functional model of only Use Cases. With these at hand we can use them to construct a Behavioural Model – namely a Sequence Diagram.

Now we have at hand a detailed Sequence Diagram. With this we can move on forth to the Class Layer and construct detailed class diagrams. In other words, you can go from one Model to another like so:

Functional Model  ->  Behavioural Model  ->  Class Model

Use Cases  ->  Sequence Diagram  ->  Design / Domain Class Diagram

Now you;re going to ask me how aren’t you? Okay, fine :)

With a use case diagram, you must have paired with it a use case description. Now, as described in the use case post, a use case description has Primary Flow of events. This is what we use in order to generate the sequence diagram. Now, once a sequence diagram has been created – a post will be done later on to show how we do this – we now have some examples of classes that can be used to create a basic domain model, and the from that domain model we create a design class model -  and wallah!

Now, as stated, I am going to be creating posts on how to construct:

• Sequence Diagrams


• Communication Diagrams


• State Diagrams


• Activity Diagrams


• and i think that’s it? if not please leave a comment ^_^