THE UNIVERSITY OF THE WEST INDIES. Answer ALL questions. Marks for each question are given in the margin. This exam is worth 60 marks

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1 THE UNIVERSITY OF THE WEST INDIES EXAMINATIONS OF MAY 2004 Code and Name of Course: EE29B Introduction to Software Engineering Paper: Date and Time: Duration: Three Hours INSTRUCTIONS TO CANDIDATES: This paper has 5 pages and 4 questions Answer ALL questions. Marks for each question are given in the margin. This exam is worth 60 marks Q1. (a) Describe the role and relationship between the following actors in software development. 5 marks Customer User Developer (b) The following list of the nine phases in software development is given in random order. Arrange them in the correct order. System design Integration testing Program design Maintenance System testing Requirements analysis Implementation Unit testing System delivery (c) Using the phases of software development given in the previous question, associate the phases with the following actors. Note that an actor may be associated with more than one phase. Analyst Designer Programmer Tester Trainer c The University of the West Indies 5 marks

2 page 2. Question 1 is worth 1s Q2. (a) Explain, with the help of a diagram, the prototyping model as used in software development. (b) List any instances when it is inappropriate to use the prototyping development model. Explain your answer. Question 2 is worth 8 marks Q3. A customer has asked your development team to develop an Point of Sale (POS) for managing their grocery. The cashier records each item purchased by entering the item code and quantity. The purchase price is then computed and the payment processed by the POS. The POS has to also interact with other systems in order to perform its job. For example, to accept credit card payments, the POS must interface with the credit card company s system. The next step is to create a conceptual and technical design. In the questions that follow, select the most appropriate answer. (a) Select the most appropriate answer. The conceptual design is felt to be of value because it will allow the customer owner to check... a What part of the system will be responsible for tracking the size of the inventory, and how it communicates with other parts of the system. b How the price of a new item is input to the system. c What the screens that the user sees will look like, and what options users will have. (b) Which of the following are valid rationales for creating a separate technical design? a The conceptual design will be useful for communicating with the customer but not very useful as a basis for implementing the system. b The technical design should contain more information about the scanners and their interfaces to the software. c The technical design should contain more detail about the likely data structures that will be used. (c) The first draft of the conceptual design has the following characteristics. appropriate? Which are NOT a It is written in a formal design notation, so that functionality can be specified as precisely as possible. b It makes multiple references to the requirements document, in order to provide the reason for including certain system components. c It uses some of the built-in features of C++, in order to better make the argument for choosing this language for use in the implementation.

3 page 3. (d) The development team has decided to divide the system into three subsystems: The inventory subsystem, which takes care of maintaining the number of items in the store. The cashier subsystem, that interacts with the cashier to accept payments from customers. A logging subsystem, that records all transaction for later auditing. This choice of subsystems was chosen to minimize the communication between subsystems. Both the inventory subsystem and the logging subsystem will communicate with the cashier subsystem but not with each other. Which of the following best describes the design at this level of abstraction? Explain your choice of answer. i. High coupling, high cohesion ii. High coupling, low cohesion iii. Low coupling, high cohesion iv. Low coupling, low cohesion (e) In the initial design, the cashier subsystem is assumed to handle all of the details of the purchase, and send only a record containing the number of items purchased, purchase price, and time of purchase to the logging subsystem. The relationship between the cashier subsystem and the logging subsystem is best described as which of the following? Explain your choice of answer. i. Content coupled ii. Control coupled iii. Stamp coupled iv. Logically cohesive v. Temporally cohesive vi. Functionally cohesive Question 3 is worth 1s Q4. (a) When implementation of a module is complete, it undergoes code review. In the following program fragments from an application, identify violations (if any) of good programming style that should be caught during review. Briefly explain your choice of answer. Use the following choices in your response: Generality Efficiency Formatting Documentation No violations i. void PrintMovieList(MovieList *movies) { MovieList *lp = movies; while ( lp ) { cout << *lp << "\n"; lp = movies->next; 2 marks

4 page 4. ii. double ValidateParts (PartsList &bundle, PartsList &parts) { /* Validate and calculate the total value of the parts in the bundle. If a part in the bundle does not exist in the parts list, return -1. If all parts in the bundle exist in the parts list, return the total value for all parts in the bundle. */ 2 marks double total_value = 0; for (PartsList::size_type i = 0; i!= bundle.size(); ++i) { if (!loans.exists(bundle[i])) return -1.0; for (PartsList::size_type i; i!= bundle.size(); ++i) total_value += bundle[i].getvalue(); return total_value; 2 marks iii. /* if the loan amount is greater than 275, it is a jumbo loan */ if ( l->getamount() > 275 ) { type = JUMBO; if (l->getprofit() > 10) /* if the profit is greater than 10, add the loan to the bundle */ bundle->addloan(l); else /* a regular loan */ type = REGULAR; (b) In a function of a module in a program, a variable does not get initialized properly. Which type of testing would be most likely expose this defect? Explain your answer. a unit testing b integration testing c acceptance testing d installation testing e performance testing (c) A function X in component A requires a pointer to an integer to be passed as an argument, but a call to the function X in component B passes the value of an integer instead. Which type of testing would most likely expose this defect? Explain your answer. a unit testing of component A b integration testing of components A and B d installation testing e acceptance testing (d) The cashier subsystem is supposed to allow the user to choose whether or not a VAT receipt is printed, but the print function has not been implemented. Which type of testing would most likely expose this defect? Explain your answer.

5 page 5. a unit testing b integration testing e function testing (e) A configuration file used by the logging subsystem is not placed in the correct directory in the customer s environment. Which type of testing would most likely expose this defect? Explain your answer. a integration testing b installation testing e function testing (f) The customer is unhappy with the number of screens that must be traversed before getting to the items list screen, a screen accessed frequently when using the system. Which type of testing would most likely expose this defect? Explain your answer. a integration testing b installation testing (g) A function with an input domain of the set of all real numbers is tested with sets of positive integers, negative integers and 0. In all of the tests, the function performs properly. Is is safe to assume that the function has been tested thoroughly and will perform properly? Explain your answer. Question 4 is worth 30 marks END OF QUESTION PAPER