Midterm Fall 2007
October 31, 2007
1. Maximum Software is a developer of fourth generation programming languages. In order to support its customers, Maximum Software provides a help desk based on a toll free telephone line.
When a call comes in, the customer is routed to the first available consultant. This consultant has a general knowledge of information systems and Maximum’s products that enables this person to answer simpler questions. The consultant always uses a database of questions and answers in providing help. If the consultant concludes that the customer’s inquiry necessitates knowledge beyond help he can provide, the consultant routes the call to a specialist.
The specialists are usually former software developers who can guide the customer through troubleshooting procedures based on their deep knowledge of particular products of Maximum. If the memorized analytical strategies are not successful, a specialist may look for ideas in a knowledge base of past problems and solutions. Based on the available information, create a use case diagram to represent this help desk system. (8 marks)
1. Solution:
Element Marked / Marks Each / Total Elements / Partials / Total MarksActor / 0.5 / 2 / no / 1
Use Case / 1 / 4 / yes / 4
Extend/Include Relationship / 1.5 / 2 / no / 3
System/Diagram Name / 1 / 1 / no / 1
9
Explanation: This help desk system contains four processes, of which two are manual (Consultant’s “Provide basic help to customer” and Specialist’s “Provide specialist help to customer) and two are mostly automated (Consultant’s “Check questions and answers Database” and Specialist’s Retrieve Knowledge Base”). The functions on either actor side can be thought of as sub-systems. Indications of the include and extend relationships are in the underlined pieces of text in the questions.
2. Super Bank has multiple branches, and each account is serviced by one branch. Each branch is tracked on a branch number, address, and phone number. The bank has personal and commercial customers. Customers have accounts, and each account is keyed on a number and contains information on the balance and the date when it was opened.
Customer information includes the customer number, name, and mailing address. Commercial customers also have attributes for credit rating, contact person, and contact person phone. Personal customers have attributes for home phone and work phone.
Create a simplified class diagram (no methods and multiplicity included) that is based on this description. Use all the information available.
2. Answer:
Note: Multiplicity is shown just for study purposes.
Marks:
Element Marked / Marks Each / Total Elements / Partials / Total MarksClass / 0.8 / 5 / no / 4
Generalization (if not correct symbol -.25 or .5) / 1.7 / 1 / yes / 1.7
Association other than Generalization (must be named or ½ mark) / 2 / 1 / yes / 2
Attribute / 0.10 / 13 / yes / 1.3
9
3.Using the document below, create an activity diagram for a real estate agency’s information system.
Use Case Name: / Change Listing InformationScenario: / Update existing listing information
Trigger: / Agent needs to change listing information
Actors: / Real Estate Agent
Flow of Steps: / Actor / Computer System
1. Enter agent ID
2. Enter listing number
3. Enter listing updates
4. End the session / 1. Verify agent ID
2. Retrieve listing and display it
3. Validate that agent has the privilege to change the listing. Save changes.
Exception Conditions: / 2. If the listing not found, display “No listing available. Enter new number.” Wait for next input.
3. If no update listing privilege, display “Listing change not allowed” and end the session
3. Solution:
Marks
Element Marked / Marks Each / Total Elements / Partials / Total MarksActivity
(activities “End session” are optional) / 0.5 / 9 / yes / 4.5
Decision Point (question specified) / 1 / 2 / yes / 2
Loop (Flow back to “Enter listing #) / 1 / 1 / 1 / 1
Flows must be correct
Missing flow = -0.25;
Violation of flow (sequence of activities) = -0.5. / 1.5
Start & End point / 0.5 / 2 / no / 1
10
4. Below is the activity diagram for the Quality Building Supply Sales System. Quality Building Inc. sells various constructions items, such as sand, cement, wood frames, plumbing elements, doors, and windows. The use case presented captures a sales transaction.
Use all the information available in the diagram to create a class diagram (the simplified version with no methods and multiplicity included).
4. Answer:
Element Marked / Marks Each / Total Elements / Partials / TotalClass (proper name, indicated attributes) / 0.8 / 5 / yes / 4
Associations (each mark breaks down on 2 elements: correct classes linked, and relationship name – ea. 0.5) / 1 / 4 / yes / 4
Attribute / 0.25 / 6 / no / 1.5
9.5
Short Answers:
1. Describe parts of an information system.
Marks: 4
The common description of IS includes: data (input, inside the system), software, hardware, and procedures. (each 0.5 marks)
For example, a customer order system contains data on orders placed by customers, software is the package used for creating a database of orders, hardware is a computer on which the database and its data arestored, and procedures are those for manipulating software and hardware, for entering data and any manual activities included in the system. (each 0.5 marks)
2. Explain relationships between use case diagram and
a) information system
b) use case description (intermediate, full)
c) activity diagram.
Answer (marks: 2 ea., sum=6 )
a) Use case diagram presents main functions in an IS (1 mark), so an IS can be seen as a set of functions (use cases) performed on data (1 mark).
b) Use case diagram names a function (1 mark), while use case description shows a breakdown of steps in the function (1 mark).
c) Activity diagram presents the same steps of a system functionas use case description (1 mark), but it does it graphical rather than textual format (1 mark).
True/False
(Note: Just explanations given just for questions with about 50% or less success rate)
1. Prototyping is a necessary part of collecting system requirements via focus groups.
F
2. Only automated processes are included in an information system.
F
3. The amount of iteration in a project depends on the complexity of the project.
T
4. In a banking system, the checking of the customer’s credit history in the process of lending a loan would be modeled as an extend use case.
F. Credit history must be checked before deciding on lending a loan, this is an include case; the question is taken from the lecture on use cases and the particular figure used.
5. In the Unified Process (Object-Oriented) life cycle, some working software is tested and reviewed with system users at the end of each iteration.
T
6. An internal business event is the event that happens inside a company.
F, internal business event happens inside the computer.
7. Forms and reports should be included for discussion in user interviews.
T, forms and reports track data inputs and outputs, and the core part of an IS is data
8. A break down of building into room, hall, lobby and so on can be represented by a generalization-specialization relationship.
F. This “breakdown” is a part-whole relationship since the building consists of these parts and the pars cannot exist outside of the building. However, in everyday language we use the word “breakdown” liberally, for both generalization and part-whole relationships.
9. Every use case must be linked to at least one actor.
F
10. Instead of an outside process updating data in an object, these data are updated only by the object’s internal processes.
T
11. Estimating whether a system development project can be completed with a minimum disruption of operations is part of determining economic feasibility of the project.
F
12. A class is assumed to know how to add a new instance, update values, and report information about itself.
T. This fact is part of definition of class; in other words, every class contains these methods which are mirrored in CRUD use cases.
13. The actor in a use case is always a person performing a particular task.
F. Actor can be another system a piece of hardware, department, etc.
14. A single use case in a use case diagram always corresponds to a single activity diagram, even when the use case hasscenarios.
F. A use case presented by an oval in use case diagram can have different scenarios, and each scenario must have a different activity diagram. The question is from the master example in the textbook – The RMO customer order system, with the telephone and Web scenario that are undistinguishable in the use case diagram.
15. Many-to-many associations often involve additional data that must be recorded.
T
Multiple Choice
(Note: Just explanations given just for questions with about 50% or less success rate)
16. _____ is the process of understanding and specifying in detail what an information system should do.
a.Information modeling
b.Systems analysis
c.Information building
d.Systems design
B
17. The message "drawYourself()" is sent to two types of objects. One object responds by displaying a bar chart. The other responds by displaying a photographic image. Which term best describes this system characteristic?
a. Inheritancec. Generalization
b. Compositiond. Polymorphism
D
18. The Unified Process is _____ driven.
a.data modelc.program
b.use cased.activity
B, part of additional information on UP; also the logic that 3150 follows
19. The _____ approach is an SDLC approach that assumes the various phases of a project can be completed entirely sequentially.
a.waterfallc. prototype
b.artifactd. object-oriented
A
20. _____ is a system development process in which work activities - analysis, design, and implementation - are repeated until the system is closer to what is ultimately needed.
a.Decompositionc.Multiplicity
b.Iterationd.Reuse
B
21. Which of the following is completed in the inception phase of the Unified Process (Object-Oriented Approach)?
a.prepare the deployment
b.resolve high risks
c.design and implement the core architecture and functions
d.produce rough estimates for cost and schedule
D. Inception phase comes first, and so the only planning activity listed is the right choice.
22. In systems analysis and design, which of the following does NOT belong to the concept of object?
a. A thing that is important to track, because it is important for business.
b. One of a series of similar items, yet uniquely identifiable.
c. A data structure that can be transformed by external processes.
d. An entity based on the principle of encapsulation.
C. Data in a class can be accessed only by the methods of that class, not external functions.
23. Expenses for developinginformation systems are significantly reduced owing to
a.use of UML
b.observation and think-aloud technique
c.inheritance
d.encapsulation
C. Owing to inheritance system developers do not have to define each data structure anew, which saves development time and therefore expenses. UML is just a diagramming technique.
24. A(n) _____ is a type to which all similar objects belong.
a.classc.attribute
b.methodd.instance
A
25. _____ combines attributes and methods into one unit and hides its internal structure of objects.
a.encapsulationc. inheritance
b.information hidingd. polymorphism
A
26. Which of the following is the action that a system analyst should include in a bank account system:
a. Mark getsa cheque for his birthday.c. Mark decides to deposit the cheque.
b. Mark wants to buy a car.d. Mark makes a deposit in his savings
account.
D
27. Which of the following is an example of a UML diagram?
a.screen layoutc.use case description
b.event tabled.use case diagram
D
28. The first fact-finding task for an analyst usually is to _____.
a.review existing reports, forms, and procedure descriptions
b.distribute and collect questionnaires
c.build prototypes
d.conduct JAD sessions
A
29. Inheritance relationships exist between:
a. instances and classes.
b. a superclass and subclasses.
c. a whole class and part classes.
d. attributes and methods.
B
30. Each employee has a salary, and salary is represented in a certain amount of dollars. A system analyst that translates this business fact into a system requirement should model salary as
a. class
b. process
c. attribute
d. association
C
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