1. Review For Exam 3

2. Managing the Development of IS - I

3. Systems Development Methodology?
The process companies go through to develop and maintain an information system
Framework for successful IS development
A System Development Methodology is used
For building a new system
Or for modifying an existing system
Examples of SDM:
System Development Life Cycle ￭ Prototyping
Joint Application Development ￭ Rapid Application Development

4. Questions Which of the following is true about SDM?
They provide guidelines for developing IS and maintaining them which includes upgrading and improving them.
SDM are needed when a brand new IS has to be developed, but you don’t need to use a SDM when it comes to modifying an existing IS.
When a company is engaged in developing an IS, the process involves the company’s employees who would be the future users of the IS, and IS professionals like system analysts and programmers. But it doesn’t involve the company’s management
All of the above

5. Traditional Systems Development Life Cycle (SDLC)
Planning
Analysis
Seven phases
Planning 5) Testing
Systems Analysis 6) Implementation
Systems Design 7) Maintenance
Development
Typically one phase needs to be completed before beginning the next
Problem in later phase may require return to previous phase
Design
Development
Testing
Implementation
Maintenance

6. Question
In SDLC, the 7 phases are typically followed in a sequential order, which means we don’t return to a previous phase in any circumstances
True
False

7. System Development Schedule
Planning
Feasibility Analyses
System Development Schedule
Feasibility analyses
Technical Analysis
Do the technologies exist to develop the system?
Economic Analysis
Can the organization afford the system?
Will it provide an adequate Benefit?
Operational Analysis (i.e. assessing the human element of the proposed system)
Resistance to change
Organizational politics
System development schedule
Is the proposed development time line realistic?
Is the programming team available during Programming step?
Planning performed by Project Manager using
Search and investigation (e.g. for technical analysis step)
Total Cost of Ownership analysis
Project Management software

8. Systems Analysis
Analyze current system
Define new system requirement
Systems analyst works with company to understand the problem fully and to detail the requirements of the proposed system
Step 1: Analyze current system
Objectives:
Understand what things are done and how (business processes)
Identify any problems associated w/ current business processes
Techniques:
Talk to employees (potential users)
Conducting interviews
Observe employees at work

9. Systems Analysis Step 2: Define new system’s requirements
Analyze current system
Define new system requirements
Step 2: Define new system’s requirements
Main Objective:
Specify What need to be done (not how to do it)
To be defined:
Input requirements (nature of data, source, etc.)
Processing requirements
Output requirements (Types of reports, content, etc.)
Storage requirements
Tools and techniques
Data flow diagrams (DFD)
Start with high level process
Add more levels with increased levels of detail
Computer-Aided Software Engineering (CASE) tools
Software that eases the systems development process

10. Data Flow Diagrams (DFD)
Process
. Symbolized by a rectangle or a curved rectangle.
. Action performed by people of organizational units in order to transform input into output OR Action performed by people in the organizational units to help the units achieve their objectives
. Symbolized by an arrow. . Shows data being passed from or to a process
Data flow
External Entity
Symbolized by a square, an external entity is something (person, group, department, etc.) outside the system that interacts with the system by providing input or receiving information.
Data storage
Used to store data in the system. Represents a file, a database, etc.

11. DFD Exercise
You should be able to answer Questions 1, 2, and 3 of the Lincoln Pizza’s ordering system DFD exercise. Hardcopies were given in class. You can also get a copy in D2L. Once in D2L, check the material for Monday 11/28. The DFD exercise is under the Questions & Exercises link.

12. Systems Design
Using the requirements from Systems Analysis phase to design the new or modified system.
Logical systems design
Details the system’s functionality (what it should do?)
Uses Structure charts to create top-down representation of system’s modules
Uses System flowcharts to show relationships between modules
Physical systems design
Specifies all of the actual components (hardware, network, etc) used to implement the logical design
The design must be frozen at end of this phase to prevent the to system grow indefinitely in terms of its scope and features
Scope creep
Feature creep
Performed by system designer or (system analyst in some case)

13. Development
Programming process is usually the most difficult and time consuming in the Development process.
Development performed by programmers, database developers, and network engineers

14. Graphical illustration of the problem-solving logic within a program
Development tools
Program Flowchart:
Graphical illustration of the problem-solving logic within a program
Pseudocode:
English-language statements that describe the processing steps of a program in paragraph form.
Programming languages:
Java
C++
Visual Basic
Etc.
Code generators:
Software that generate programs that programmers could modify.

15. Testing Programmers test modules Development team do unit testing
Do they return proper outputs?
Do they handle incorrect data appropriately?
Development team do unit testing
i.e. testing how modules work together
System testing (software along with database and network component)
Verification: Testing system in simulated environment with simulated data
Validation: Testing system in real working environment with real data

16. Implementation Implementation strategies User training
Direct cutover: Quick change to new system
Parallel conversion: Old and new systems used in parallel for a while.
Pilot testing: New system installed at only one location or one department
Staged conversion: Only one part of the system installed, then another part is installed.
User training

17. Summary Questions
Book
Notes
What is a System Development Methodology? What is it used for?
2) What are the 7 phases of the SDLC methodology?
What kind of Feasibility analyses need to be performed during the Planning phase? Why is the system development schedule important?
What are the two steps in the Systems Analysis phase? What techniques and tools are used during the Systems Analysis phase?
What tools do programmers usually use during the Development phase?
What is the difference between the Verification and the Validation tests performed during systems testing?

18. SDLC: Recap Steps Key actors Tools/Techniques
1. Planning
Project Manager
Project Management software, Total Cost Ownership analysis, etc.
2. System Analysis
System Analyst, Users.
Interviews, observing users at work, DFD
3. System Design
System analyst (or system designer)
System Flowchart, Structure chart
4. Development
Programmers, database developers, network engineers
Program Flowchart, Pseudo code, programming languages, DBMS
5. Testing
Development team, Users
Unit testing, verification, validation
6. Implementation
Direct cutover, parallel conversion, pilot testing, staged conversion
7. Maintenance
internal IS staff, external consultant
programming languages
Make sure you can answer questions about System Development (see link in Notes’ section)

19. Managing the Development of IS - II

20. Prototyping A SDM that addresses:
Time consuming issue associated with SDLC
SDLC’s inability to take care of new requirements
A SDM in which the Development team uses limited set of users requirements to quickly build a working model of the proposed system – a prototype.

21. Prototyping
Actors Development team, Users System analyst, programmer Users System analyst, programmer
Identify basic requirements
Develop a prototype
Is User satisfied?
Use the prototype
Revise the prototype
Operational prototype
Develop final system (improved prototype)
YES NO

22. Prototyping Advantages Disadvantage Working model ready quickly
Works in situation where requirements are changing
Works in situations where users cannot explicitly express their requirements
Disadvantage
Only a limited number of users involved. So, subject to potential implementation problem.

23. Joint Application Development (JAD)
A SDM that addresses:
The limited scale of users involvement problem of Prototyping
Potential implementation problem due to limited users involvement
A SDM that brings together the Development team and a significant number of users to define system requirements and develop a prototype.

24. Joint Application Development (JAD)
Objectives Identify agreed upon systems requirements Test the system and identify agreed changes
Identify a valid sample of users
Set a JAD team (Users, IS professionals, scribe)
Run the 1st JAD session (JAD team + Facilitator)
Develop system prototype (based on agreed requirements)
Run the 2nd JAD session (JAD team + Facilitator)
Improve system prototype (based on JAD session results)

25. Question 2
Which of the following is true about a JAD facilitator? (Choose all that apply)
Could be an outside consultant
Is the scribe who takes notes
Is responsible for coordinating the JAD sessions
Is responsible for developing the system based on the agreed upon requirements
All of the above

26. Joint Application Development (JAD)
Advantages:
Helps alleviate conflicting requirements
Its gGreater users involvement leads to greater user acceptance of final system
Disadvantages
Could be expensive and time consuming

27. Questions
In addition to reviewing these class notes, you should also review the related Review questions seen in class.
Copy of the review questions are available in the Monday (11/28) – Review folder in D2L

28. The Internet and eBusiness

29. Brief history of the Internet
Make sure you know what DNS is used for.
1969
The Defense Advanced Research Projects developed ARPANET, the precursor of the Internet
1971
Ray Tomlison invents
1979
USENET newsgroups created at Duke University and the University of North Carolina
1984
Domain Name System (DNS) established
1991
Tim Berners-Lee creates the World Wide Web
1994
First online shopping mall, first spam , first pizza ordered online, first advertisement banner
2000
A major denial of service attack brings down websites such as Yahoo!, Amazon.com, and eBay
2002
Denial of service attack knocks out 8/15 root DNS servers

30. Accessing the Internet (www)
Network
Web Browser
Webserver
Software
Packet
Packet
Route
Router
User PC needs: - Workstation Operating System - TCP/IP - Web browser (e.g. Internet Explorer)
- Internet access (e.g. thru an ISP)
- IP Address (e.g )
Webserver needs:
Network (or Server) Operating System - TCP/IP - Domain name (e.g. eiu.edu)
Internet access
IP Address (e.g )

31. Internet applications/services
File transfers
Instant messaging (IM)
Newsgroups
Streaming audio and video
Internet telephony or VoIP
World Wide Web (WWW)
Portal

32. Portal A portal is Examples of portal: yahoo!, msn, aol
A Web site that offers a broad array of resources and services; such as
newsgroup
Serach engines
Online shopping malls
Examples of portal: yahoo!, msn, aol

33. Best way to prepare
After review the Internet & eBusiness PPT notes, make sure you can answer the following questions:
Internet & eBusiness Review Questions posted to Monday (11/28 – Review folder in D2L.

34. Information Security

35. Best way to prepare
Review the Information Security PPT notes and make sure you can answer the following questions:
Information Security Questions posted to Monday (11/28 – Review folder in D2L.