CSCC40 midterm........October 24, 2003........page 1 of 8

UNIVERSITY OF TORONTOScarborough College

CSCC40 Analysis and Design of Information Systemsmid-term test with ANSWERS

October 24, 2003 5:30 to 7:30 PM Rooms B355 and B516Duration: 2 hours.

One 8 1/2 by 11 hand-written aid sheet is permitted.

Student Number _____________________________________________________________________

Name _____________________________________________________________________ (surname) (given name)

INSTRUCTIONS:1. Check this examination paper. There are 8 pages including this cover page.2. Print your name and student number on this examination paper, and initial the top of each page.3. Print your name and student number on the examination booklet.4. Answer all section A questions on this examination paper.5. Answer all section B questions in an examination booklet.6. Note that the mark for each question is given in the right-hand column.7. The total number of marks is 106, but this test is worth 25% of your final grade. HINTS:1. Read each question carefully.2. Write legibly and understandably. An unreadable answer receives no credit.3. For each question, spend time appropriate to the number of marks given for that question.4. If there seems to be ambiguity in the question, ask the invigilator for clarification or state your

assumptions and continue. If your assumptions are reasonable and don’t trivialize the problem, youwill probably receive full credit.

CSCC40 midterm........October 24, 2003........page 2 of 8

SECTION A – answer these questions in this examination paper.

A1. Strategies evolve at three levels: business, information, and technology. [6]An example has been give for the first statement. Give examples for each of the remaining threestatements.

one mark for demonstrating understanding and one for an appropriate example(the answers below do not include examples, because there were so many possibilities)

statement example

A company's business strategysets goals for its information

systems strategy.

If they decide to sell their products internationally, the information systemsmust make the product information available on the web.

A company's information systemsstrategy sets goals for its

information technology strategy.

• the need for specific applications defines what technology is neededto support these application

• the functionality and database requirements determine thehardware, DBMS, networks, etc. that are needed

A company's informationtechnology strategy enables itsinformation systems strategy.

• if you have good tools (good technology) you have the opportunity todevelop good application systems

• where IT has skills and technology, they can suggest/initiateprojects that provide better information

A company's information systemstrategy enables its business

strategy.

• good systems aid the company in meeting it’s goals by making themeasier to achieve

• good application systems can sometimes produce side benefits aswell as providing the functionality that was asked for

A2. IT professionals can encounter several problems during the analysis and design phases [6]of a project. For each problem listed below, give ONE techniques or practice they can use.

problem technique or practice to reduce the risk or impact

the system is too large tobe understood by any

one person

2 marks for partitioning, abstraction, information hiding or O-O analysis design

1 mark for incremental development, corporate data model, etc. (but 2 marks ifwell explained

technology is changingall the time

2 marks for feasibility studies, spiral SCLC, explanations such as “get logicaldesign right to make physical design more flexible”

1 mark for abstraction (2 if well explained)

user requirements changeall the time

2 marks for change management, good documentation

1 for prototyping (2 if well explained)

CSCC40 midterm........October 24, 2003........page 3 of 8

A3. There are several ways to measure the financial feasibility of a proposed project. [6]For each of the following measurements, explain what it shows that the others do not.Do not give definitions, focus on the differences.

measurement what it demonstrates that other measurements do not

benefit to costratio

it’s a good, quick evaluation that can be used to compare projects or evaluate economicfeasibility -it’s usually the first calculation

return oninvestment

compares putting money into the project against the alternative of investing it or putting themoney into another project

break-evenpoint shows cash flow and lets you know when the project starts making money

A4. Some project scenarios are described below. Based on the brief (and incomplete) [4]descriptions, name the SDLC you think is being used. Assume that no two scenariosrepresent the same SDLC. Each scenario may or may not have two possible answers.

scenario SDLC

There are two programmers sitting at one workstation discussingthe next segment they will code together at that workstation.

extreme programmingor agile SDLC

(development got 1/2 mark)

A team of systems analysts are negotiating with users about whatfeatures to include in the next version of an installed system.

incrementalor spiral

(analysis got 1/2 mark)

The project manager is asking the testing team to start loggingoutstanding bugs since the system is going live next week.

wild westor none

(testing or management got 1/2 mark)

Internal auditors have asked for documented validation ofrequirements and an up-to-date risk analysis before

recommending the next system features to be considered.

spiralor incremental

(risk analysis got 1/2 mark)

A5. Define “critical success factor”. [2]

If this measurable and specific milestone or minimum is not achieved, the project or process cannotbe called a success.

CSCC40 midterm........October 24, 2003........page 4 of 8

A6. Give two ways of validating requirements, and two ways of managing requirements. [4]Assume the requirements have been or will be documented.

validatingrequirements

validatingrequirements

note: validate asks “did we do the right thing?” and verify asks “did we do it right?”walkthroughs with usersformal approvalseffective prototyping

managingrequirements

managingrequirements

prioritizeperform risk analysisformal change management (paper trail)cost/benefit calculationsdecomposition, abstraction etctraceability

A7. Requirements can be classified. For each requirement in the first column [4]select only one of the two classifications in the next two columns.

The customer inquiry responses must take less than 2 sec. r functional r non-functional

Order entry and all order maintenance needs a full audit trail. r emergent property r specific task

User training on the working system will take less than 10 days. r product r process

In 5 years the system has to handle 400 orders per day. r volatile r stable

• response time is a non-functional requirement because inquiry is not the only function that needs areasonable response time

• audit trails mean that all database updates (not just those by order entry) must be recorded• after a system has been installed, the amount of training needed depends on the system, not the process used

to develop it• a 5-year prediction is unreliable

A8. Modularity, information hiding and partitioning are necessary for large projects. [4]For each of the project phases below, give an example of how these techniques are used.Do not give the same example twice.

how modularity and information hiding is used

analysis• easier to validate requirements• can ignore the “how” while working on major concepts and user-related issues

design

• component reusability is more likely• low coupling and high cohesion make components more feasible for development and

maintenance• details and overview can be worked on separately

testing• better control, easier to plan good testing• tests themselves can be more thorough• black box testing is made possible

maintenance• easier to understand systems – fewer maintenance errors• change in one area has less impact in other areas• can split the work among separate teams

CSCC40 midterm........October 24, 2003........page 5 of 8

A9. Forward and backward traceability are necessary characteristics in a system. [4]Give an example of how traceability is useful.

how the traceability is useful (how it’s used)

forwardtraceability

backwardtraceability

testing (test planning for forward traceability and finding bugs for backward traceability)

audit trail – had to be one of the items for either forward or backward traceability

very few other answers got more than partial (very partial) marks

A10. The V-model maps time against the level of abstraction. [4] Explain the message behind this model. (Do not draw the V-model).

had to mention: abstraction cannot test original requirements until system installed

A11. The left hand column gives examples of well-designed user interfaces. [5] Match them up with the terms on the right.

garbage can and printer icons ____

acknowledgement of completed saves and deletes ____

consistent labelling and placement of the help and print buttons ____

desktop and file folders ____

the presentation of the font to be selected is in the form/shape of the font ____

removing or greying out buttons when they cannot be used ____

E or A

D

C

E or A

F

B

A. mental modelsB. forcing functionsC. automaticlearningD. feedbackE. affordanceF. mappingfunctions

(if you got 5 right, the 6th one had to be right too)

CSCC40 midterm........October 24, 2003........page 6 of 8

A12. Indicate whether the following statements are true or false. [17]

True False

TrueIn the value chain model of a business, both support and primary activities can beautomated.

TrueManagement information systems get their data primarily from transactionprocessing systems.

FalseSystem controls include feedback, which is the users’ response or reaction to thesystem output.

True Management support systems involve the processing of routine business activities.

False Both waterfall and structured diagrams are methodologies.

True Business process reengineering often necessitates software changes.

FalseCASE tools check models for consistency, completeness, syntactical correctness andrelevance to user requirements.

FalseData-oriented development means that data is designed specifically for eachapplication.

FalseDespite the changing nature of projects and their problems, methodologies aresuccessful in fulfilling all project and methodology objectives.

TrueIn order to be useful, any IS methodology must include techniques for discovering,analyzing, and modelling the relevant content for each of the following abstractviews: data, process and temporal.

TrueIt is necessary to complete the logical design before making final decisions about thephysical design.

TrueIterations are almost inevitable, because inadequacies in the requirements analysismay become evident during design, construction and testing.

True Partitioning must start at the analysis phase.

True FalseThe maintenance effort is not affected by the methodology used in creating thesystem. bonus point –either one can be argued

TrueThe spiral model includes a repeating cycle of planning, risk analysis, engineeringand evaluation throughout the project.

False Turnaround documents are only used internally within the source organization.

TrueYou can use either structured or object-oriented analysis when using either thewaterfall or prototype methodology in your project.

CSCC40 midterm........October 24, 2003........page 7 of 8

A13. Give four objectives to keep in mind when designing input. [4]

There are lots of answers for this...• minimal user input – enter data only once• effective and useful feedback• easy to understand/comply with controls• prevention of input errors• data entry at source wherever possible• low cost• strict security• audit trail

SECTION B – answer these questions in the examination booklet.

B1. Below is a table of data that is not normalized. [6]Explain why it is not first, second nor third normal, giving an example for each reason.

studentnumber

studentname

studentmajor

studentaddress

coursenumber

coursetitle

term prof. prof’sdepartment

grade

356 Sam CS Res4 CSC09 Database fall2002

Smith CS A-

356 Sam CS Res4 CSC06 Java fall2003

Lee MS B-

984 Jim Mth Res58 MAT14 Calculus fall2002

Jones CS B+

You had to know the rules for normalization:1NF = no repeating data (e.g. = student name and major... always same for student

number2NF = non-key attributes depend on entire key (e.g. = ... that depends on what you

decided was the key in this case)3NF = non-key attributes do not depend on other non-key attributes (e.g. = prof. depends

on course and term, and in this case either one may not be a key)

CSCC40 midterm........October 24, 2003........page 8 of 8

B2. Using the data in the tables above, draw an ERD based on normalized data. [10]For each entity, using any convention, give the primary key, foreign key(s) and non-keyattribute(s).

most common problems included situations where the following capabilities were not possible in yourdiagrams:

• student can take a course a second time• a prof. can teach more than one course• a course can be given more than once

CSCC40 midterm........October 24, 2003........page 9 of 8

B3. VehiclesUnlimited rent cars and trucks to individuals and to businesses.The systems analyst working to develop a rental system for VehiclesUnlimited has just started thediagram below. At a meeting with clients the systems analyst learns the following:

- rental agreements with individuals are quite different from those with businesses(they carry different information)

- individuals renting a vehicle must pay when they return the vehicle

- but businesses pay to an Accounts Receivable system (it already exists and is not in thescope for this system) and this rental system just sends the rental agreementinformation to that Accounts Receivable system

- managers not only set rental rates, they change them from time to time

For the system, with its new requirements:

(a) Redraw the DFD to reflect the new requirements. Ignore process numbering at this point. [10]

Marks were given for:• the data flow between process update rates and the rental rates data store had to be a double headed

arrow (that means update)• Accounts Receivable had to be an external entity with some kind of rental information flowing to it• there had to be one of the following situations ( both would have been ideal, but no one managed it

anyway):o separate entities for private customer and for business customer – with all flows coming

from and going to themo separate data stores for private and for business rental agreements – with all add, update

and read flows that are necessary.Marks were deducted for mistakes such as flows between entities and data stores, processes with no output,etc.

CSCC40 midterm........October 24, 2003........page 10 of 8

(b) Draw the context level diagram for the rental system. [4]

(c) The diagram does not include the rental agent who actually works with customers to set up [2]the rental agreements. Should the rental agent be included in the diagram? Explain.(Do not change your diagrams to include the rental agent –just answer the question.)

Definitely NO. The rental agent does not provide information –it all comes from the other entities.

(d) VehiclesUnlimited already has the following systems: payroll, accounts receivable, [4]accounts payable, and vehicle maintenance. Draw a hierarchy chart for VehiclesUnlimitedthat includes all its systems and contains details only for the rental system.

(e) Now add the process numbers to your diagram (a). [2]the above numbers had to match the ones in the DFD