Deck 17: More on UML

Question 1

Is UML a methodology? Carefully explain your answer.

Answer 1

The full form of UML is Unified Modelling language. It is used to explain the software development process using object oriented analysis and unified process.
• UML is a language which models software using UML use cases, class diagrams, use case diagrams, interaction diagrams, activity diagrams etc.
• UML is a language using which developers specify and analysis a software system.
• UML is not a method that tells how to develop a software product instead UML provides notations which helps in how a software product can be analysed and structured so that the development of software product can be done.
• UML is a language which can be described as a simple tool for expressing the ideas (software product).
Thus, UML is not a methodology. It is a notation that can be used in conjunction with any method.

Question 2

Use UML to model airports. (Hint: Do not show any more details than are strictly needed to answer the question.)

Answer 2

The full form of UML is Unified Modelling language. UML is a language which models software using UML use cases, class diagrams, use case diagrams, interaction diagrams, activity diagrams etc. UML is a language using which developers specify and analysis a software system. It a simple tool for expressing the software product.
The figure 1 below shows the simplest class diagram of Airport class. Figure 2 represents the details of Airport class in which the upper part of the Airport class represents the instance and the lower part represents the methods.

Question 3

Use UML to model chocolate cakes. A chocolate cake is made with eggs, flour, sugar, baking powder, milk, and cocoa. A chocolate cake is mixed, baked, frosted, and then eaten. To prevent unauthorized individuals from baking a chocolate cake, the ingredients are private, as are all but the last operation.

Answer 3

The full form of UML is Unified Modelling language. UML is a language which models software using UML use cases, class diagrams, use case diagrams, interaction diagrams, activity diagrams etc. UML is a language using which developers specify and analysis a software system. It a simple tool for expressing the software product.
• The class diagram of cake class is shown. The notation Cake class is used to specify object of the class.
• The upper part of the diagram represents the instance of Cake class which are eggs, flour, sugar, baking powder, milk and cocoa.
• The lower part of the diagram represents the operations done on the instance of the class which are mix, bake, frost and eat.
• The prefix + denotes that attributes and methods are public which can be invoked anywhere in the software. The prefix - denotes that attributes and methods are private which helps in information hiding. The UML for modelling chocolate cake with the given instructions is as follows:

Question 4

Add a note to your diagram of Problem 17.3 pointing out that the cake you modeled is a chocolate cake.

Question 5

Use UML to model the following: Turn on the oven. Mix the ingredients for a chocolate cake. Mix the ingredients for an apple pie. Place the (raw) cake and pie in the oven. Remove the chocolate cake when it is done. Remove the apple pie when it is done. Turn off the oven.

Question 6

How does your UML model of Problem 17.5 cope with the fact that we do not know, from the information given, which of the two items is removed from the oven first?

Question 7

Modify your model of Problem 17.6 to reflect that the chocolate cake is prepared by the chocolate cake baker, the apple pie by the apple pie baker, and that the oven is switched on and off by the chief baker.

Question 8

Model chocolate cakes and apple pies using one package.

Question 9

Use UML to model dining rooms. Every dining room has to have a table, four or more chairs, and a sideboard. Optionally, it may also have a fireplace.

Question 10

Model the dining rooms of Problem 17.9 using a combination of aggregation and composition.

Question 11

Modify your UML model of Problem 17.9 to reflect that a dining room is a specific type of room.

Question 12

Use UML to model John Cage's somewhat controversial 1952 piano composition entitled 4? 33?. The piece consists of three silent movements, of length 30 seconds, 2 minutes 23 seconds, and 1 minute 40 seconds, respectively. (The title of the piece comes from its total length.) The pianist walks onto the stage holding a stopwatch and the score (in conventional music notation but with blank measures). The pianist sits down on the piano stool, puts the score and the stopwatch on the piano, opens the score, starts the stopwatch, and then signals the start of the first movement by lowering the lid of the piano. At the end of the first movement (that is, after 30 seconds of silence during which the pianist carefully follows the blank score, turning the page when necessary), the lid of the piano is raised to signal the end of the first movement. These actions are repeated for the second movement (2 minutes 23 seconds) and the third movement (1 minute 40 seconds). The pianist then closes the score, picks up the score and the stopwatch, gets up, and leaves the stage.