Midterm Fall 2006 by uPD43Brk

VIEWS: 68 PAGES: 12

									                               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
1. Solution:


                               Help Desk System

                                  Provide basic
                                 help to customer


                                           «includes»
                                                              Consultant
                                   Check Q+A
                                    Database



                                 Provide specialist
                                 help to customer

                                               «extends»
                                                                  Specialist
                                     Retrieve
                                  Knowledge Base




Element Marked           Marks Each        Total Elements   Partials    Total Marks
Actor                    0.5               2                no          1
Use Case                 1                 4                yes         4
Extend/Include           1.5               2                no          3
Relationship
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
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:

                           Customer                                                  Branch


                                                                               branchNumber
                              name
                                                                                     address
                             address            1
                                                                                      phone


                                                       has


                                                                                              1
                                                                              services
                                                                                                  0...*



                                                                                     Account
        CommercialCustomer             PersonalCustomer               0...*


                                                                              accountNumber
            creditRating
                                       homePhone                                     balance
         contactPerson
                                        workPhone                                  dateOpened
         contactPhone




Note: Multiplicity is shown just for study purposes.

Marks:

Element Marked                         Marks Each            Total Elements          Partials             Total Marks
Class                                                0.8                       5                     no                 4
Generalization (if not correct                       1.7                       1                   yes             1.7
symbol -.25 or .5)
Association other than                                2                        1                   yes                  2
Generalization (must be
named or ½ mark)
Attribute                                           0.10                      13                   yes             1.3
                                                                                                          9



                                                                                                                        3
3. Using the document below, create an activity diagram for a real estate agency’s
information system.

Use Case Name:        Change Listing Information
Scenario:             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                    1. Verify agent ID

                      2. Enter listing number               2. Retrieve listing and display
                                                            it
                      3. Enter listing updates
                                                            3. Validate that agent has the
                      4. End the session                    privilege to change the listing.
                                                            Save changes.

Exception             2. If the listing not found, display “No listing available. Enter new
Conditions:           number.” Wait for next input.

                      3. If no update listing privilege, display “Listing change not
                      allowed” and end the session




                                                                                              4
3. Solution:

                         Real Estate Agent                                  System



                            Enter agent ID                         Verify agent ID


                                                               Listing available?
                             Enter listing #                                     Y
                                                                        N

                                                                  "Error: Enter new #



                           Enter listing update                      Display listing




                                                                  Verify update privilege


                                                                                  Update
                                                                                 privilege?
                                                                    Y                N


                                                             Save changes       Error: "Not allowed"




                             End session                                             End session




Marks
Element Marked                                       Marks    Total    Partials                    Total
                                                     Each     Elements                             Marks
Activity                                             0.5      9                 yes                4.5
(activities “End session” are optional)
Decision Point (question specified)                  1        2                 yes                2
Loop (Flow back to “Enter listing #)                 1        1                 1                  1
Flows must be correct                                                                              1.5
Missing flow = -0.25;
Violation of flow (sequence of activities) = -0.5.

Start & End point                                    0.5      2                 no                 1
                                                                                                   10




                                                                                                           5
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).

                                                              Computer




                                                                                         6
4. Answer:

                                     Receipt


   Contractor
   contractorID
   name                                     issued_for
                         gets
                                    SaleTicket
            has                     total

     Account
     credit                                 contains                SaleItem



                                                             (Provided for study
                                        Item
                                                             purposes—not graded.
                                    description              The relationship between
                                    price                    Sale and Item is
                                                             many-to-many, and SaleItem
                                                             can contain quantity,
                                                             and perhaps salePrice)


Element Marked                                       Marks      Total          Partials Total
                                                     Each       Elements
Class (proper name, indicated attributes)            0.8        5              yes      4
Associations (each mark breaks down on 2             1          4              yes      4
elements: correct classes linked, and relationship
name – ea. 0.5)
Attribute                                            0.25       6              no       1.5
                                                                                        9.5




                                                                                                7
                                     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 are stored, 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 function as 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.



                                                                                           8
       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 has scenarios.
       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




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                                         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. Inheritance                    c. Generalization
    b. Composition                    d. Polymorphism
D

18. The Unified Process is _____ driven.
        a.      data model     c.     program
        b.      use case       d.     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.     waterfall      c. prototype
        b.     artifact       d. 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.      Decomposition        c.       Multiplicity
       b.      Iteration            d.       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?


                                                                                           10
   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 developing information 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.     class           c.      attribute
       b.     method          d.      instance
A

25. _____ combines attributes and methods into one unit and hides its internal structure
of objects.
       a.    encapsulation          c. inheritance
       b.    information hiding d. polymorphism
A

26. Which of the following is the action that a system analyst should include in a bank
account system:
a. Mark gets a 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 layout          c.     use case description
      b.      event table            d.     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




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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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