For each of the following terms, briefly define it and explain its importance in relation to software design:

a.    Representational gap

b.   Coupling

c.    Cohesion

Question 2 [10 marks]

In the context of domain modelling, for each of the following elements: define it, describe when it should be used, and provide an example.

a.    Description class

b.   Composition

Question 3 [10 marks]

a.   Describe the Information Expert pattern and provide an example to illustrate its application.

b.   Describe the Creator pattern and explain why particular Creator options are given priority over others.

Question 4 [7 marks]

In the context of mapping a design to code:

a.   [2] The guideline for translating design classes to code is to work from least coupled to most coupled. Briefly justify this guideline.

b.   [5] Explain how design associations with multiplicities greater than one can be mapped to code, and what should guide the choice of representation. Provide an example.

Question 5 [10 marks]

Question 5 Part 1. [4 marks]

Briefly describe architectural analysis and why it is important.

Question 5 Part 2. [6 marks]

For each of the following, provide an example and briefly explain why it is architecturally significant:

a.   An architecturally significant functional requirement.

b.   An architecturally significant non-functional requirement.

Question 6 [18 marks]

This question relates to the domain model below. This is the iteration-3 domain model for the Monopoly case study from Applying UML and Patterns, 3rd  Ed. by Larman.

Below is a list of changes to the Monopoly game.  For each change, describe precisely or draw the corresponding change (if any) that should be made to the Monopoly domain    diagram.  You should not redraw the whole diagram.

a.   [2 marks] A new move rule is introduced. If a Player P is about to move their Piece to a Square, and there is already another Player’s Piece on that Square, Player P will       instead move their Piece to the next Square without a Piece already on it.

b.   [2 marks] One of the Railroad Property Squares is replaced by another Income Tax Square.

c.    [6 marks] A new kind of square called a Park is created; there are four different Parks. Every Player is required to choose their favourite Park at the start of the game (they

can choose the same Park if they wish). However, Players can’t own Parks.

d.   [8 marks] For this change you should assume that: (i) every turn taken by a player is numbered in sequence starting with 1; (ii) Properties can be bought and sold by Players; and (iii) once a Property has been bought, it will always be owned by some Player. New rules are introduced to the game that depend on knowing the                  Properties owned by every Player in every turn.  An example of one of these rules is: when a Player lands on a Property, if they previously owned that Property they get a discount on rental based on the total number of turns for which they owned that      Property. Note that we still need to know who owns which Properties currently (as   per the Owns association).

Question 7 [27 marks]

The passage below describes the ZProcess software system. It is important that this system maintains a high degree of availability; the box below describes how this is to be achieved.

Question 7 Part 1. [5 marks]

This ZProcess system requires protected variation.  What is protected variation, what are the two different kinds of variations we need to consider, and which of these kinds is required     by ZProcess?

A partial design class diagram (DCD) showing public elements and some code snippets from the implementation for ZProcess are provided below.

+zalg

Helper_ZAlg_Library Helper_ZAlg_Service

+   apply_ZAlg(zinputs :ArrayList)  :ZOutput        +   apply_ZAlg(zinputs :ArrayList)  :ZOutput

«use»

third_party::ZAlg_Library

+    zAlg()  :ZOutput

+    zAlg(zinput :ZInput)  :ZOutput

+    zAlg(zinput1 :ZInput, zinput2 :ZInput)  :ZOutput

+    zAlg(zinput1 :ZInput, zinput2 :ZInput, zinput3 :ZInput)  :ZOutput

Question 7 Part 2. [7 marks]

What GoF design pattern is most prominent in the ZProcess design?  Describe this pattern, with clear reference to the ZProcess system as a concrete example.

Question 7 Part 3. [15 marks]

Consider a case where do_important_stuff() generates exactly two ZInputs and applies ZAlg to them.  Illustrate this scenario with a design sequence diagram, using the methods in the design/implementation elements provided above. Be sure to cover the behaviour for both  the service and library cases. You can assume that zalg is already initialised and all relevant objects already exist.

Question 8 [23 marks]

The following questions refer to the passage below which describes the Pennand ATM       (Automated Teller Machine). The sentence numbering is provided to make it easier for you to track the various elements of the description.