System Modeling and Design Assignment: Task 1-3

Task 1: System Description [10 marks]

Firstly, you must choose a business that you will model. Please describe this business, list its stakeholders (e.g. customers, staff, etc), list the important information about the business entities (e.g. products and services), and informally describe the main use cases and activities of the business. Do NOT write this as a list, it should be written in sentences and paragraphs.

If you choose a business discussed in class and your diagrams are very similar, you work could be considered as plagiarism. 

1. Identifying the main stakeholders (e.g. actors) [2 marks]

2. Identifying business entities (e.g. classes) [4 marks]

3. Describing use cases and activities [4 marks]

4. The word limit can be increased by 10% without penalty. Every further 10% after this leads to a removal of 10% of the highest possible mark. For example, 218 words is fine; 265 words would lead to -3 marks. Please ensure good use of language and grammar, and that your description matches the system you later develop. 

Part a) Use Case Diagram

Create a Use Case diagram for the system supporting your chosen business (as described in Task 1 above). [12 marks]  

1. Identifying at least 6 meaningful Use Cases (1 mark each) [6 marks]

2. Correct and non-trivial participation of actors in Use Cases (at least one example of more than one actor involved in a Use Case) (0.5 mark each) [3 marks]

3. Correct use of at least one <> and <> (1 mark for extend, 1 mark for include) [2 marks]

4. Good use of generalisation for Use Cases or actors [1 mark]

Part b) Activity Diagram

Create one activity diagram for the system supporting your chosen business (as described in Task 1 above). [12 marks]  

Marking Criteria

1. Identifying at least 6 meaningful actions (1 mark each) [6 marks]

2. At least 2 correct uses of decision nodes including guards on outgoing arrows (2 marks each) [4 marks]

The following tasks will require the use of Eclipse and the Eclipse Modelling Framework. The previous lab sessions will help you with learning the necessary techniques. 

Part a) Class Diagram
Using EMF, design a class diagram for the system of your chosen business. Use role names and multiplicities on all association ends. [17 marks]

Part b) OCL Invariants
Add three meaningful OCL class invariants to the Ecore model that follow your description in Task 1. Do this using the OCLinEcore editor (see here for details). The names of invariants must start with “inv1”, “inv2”, and “inv3” respectively. [9 marks]  

Marking Criteria

1. Class Diagram

Identify at least 5 classes with correct and meaningful class names (1 mark each) [5 marks]

Use generalisations at least two times (1 mark each) [2 marks]

Use at least one abstract class [1 mark]

Use of attributes (at least one per class) [5 marks]

At least 4 correct associations with association role names and non-trivial multiplicities (not all * or 0..*) (1 mark each) [4 marks]

2. OCL class invariants

Use attributes [1 mark]

Use of navigation leading to a single instance [1 mark]

Use of navigation leading to a set of instances [1 mark]

Use navigation via multiple associations [1 mark]

Use of if-then-else [1 mark]

Use of comparison operator (e.g. “<” or “>”) [1 mark]

Use of size(), exists(), forall() (1 mark each) [3 marks]