Review For Exam 3

Managing the Development of IS - I

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

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

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

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

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

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

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

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.

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.

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)

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

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.

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

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

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?

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)

Managing the Development of IS - II

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.

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

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.

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.

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)

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

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

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

The Internet and eBusiness

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 e-mail 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 email, 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

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. 128.150.50.9) Webserver needs: Network (or Server) Operating System - TCP/IP - Domain name (e.g. eiu.edu) Internet access IP Address (e.g. 139.67.8.3)

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

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

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.

Information Security

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.