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Fundamentals of Information Systems Fourth Edition

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Pay attention to acronyms ! LEARN THE SDLC You will need it for the rest of ... An outside consulting firm or computer company that specializes in systems ... – PowerPoint PPT presentation

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Title: Fundamentals of Information Systems Fourth Edition


1
Fundamentals of Information SystemsFourth Edition
  • Chapter 8
  • Systems Development

Includes Some content from AK ITEC 2010 F 2006
2
Principles and Learning Objectives
  • Page 339
  • Review Principles as an overview of chapter.
  • Pay attention to acronyms !

LEARN THE SDLC You will need it for the rest
of your life AND it WILL be on the exam !!!
3
Why Learn About Systems Development?
  • Important to learn how to
  • Initiate systems development process
  • Analyze your needs with help of IS personnel
  • Learn how a project can be
  • Planned
  • Aligned with corporate goals
  • Rapidly developed

See page 340
4
Participants in Systems Development
  • Development team consists of the following
  • Project managers coordinate system development
    effort
  • Stakeholders directly or indirectly benefit from
    the project
  • Users interact with the system regularly
  • Systems analysts analyze and design business
    systems
  • Programmers modify or develop programs to
    satisfy user requirements
  • Various support personnel specialists, vendors

P 341
5
Information Systems Planning and Aligning
Corporate and IS Goals
  • Information systems planning translating
    strategic and organizational goals into systems
    development initiatives
  • Aligning organizational goals and IS goals is
    critical for any successful systems development
    effort
  • Determining whether organizational and IS goals
    are aligned can be difficult

6
Information Systems Planning and Aligning
Corporate and IS Goals (continued)
Figure 8.2 Information Systems Planning
7
Systems Development Life Cycles
  • The systems development process is also called a
    systems development life cycle (SDLC)
  • Common SDLCs
  • Traditional systems development life cycle
  • Prototyping
  • Rapid application development (RAD)
  • End-user development

This classification is inconsistent with that
used for ITEC 2010.
8
The Traditional Systems Development Life Cycle
LEARN !!
Figure 8.3 The Traditional Systems Development
Life Cycle
9
The Traditional Systems Development Life Cycle
(continued)
  • Systems investigation problems and opportunities
    are identified and considered in light of the
    goals of the business
  • Systems analysis study of existing systems and
    work processes to identify strengths, weaknesses,
    and opportunities for improvement
  • Systems design answers the question How will
    the information system do what it must do to
    obtain the problem solution?

10
The Traditional Systems Development Life Cycle
(continued)
  • Systems implementation creation or acquisition
    of various system components detailed in the
    systems design, assembling them, and placing the
    new or modified system into operation
  • Systems maintenance and review ensures the
    system operates as intended and modifies the
    system so that it continues to meet changing
    business needs

11
Prototyping
  • An iterative approach to systems development

Some other references consider prototyping as
part of different phases (analysis,
implementation) of the SDLC.
Figure 8.4 Prototyping
12
Rapid Application Development, Agile Development,
Joint Application Development, and Other Systems
Development Approaches
  • Rapid application development (RAD)
  • Systems development approach that employs tools,
    techniques, and methodologies designed to speed
    application development
  • Some iterative development approaches allow the
    system to change as it is being developed
  • Agile development frequent face-to-face meetings
    between systems developers and users
  • XP programming pairs of programmers work
    together to develop robust systems quickly

13
Rapid Application Development, Agile Development,
Joint Application Development, and Other Systems
Development Approaches (continued)
  • Pages 346 347 Read carefully three times.
    Learn RAD JAD acronyms.
  • Study Extreme Programming, GSSs.

14
The End-User Systems Development Life Cycle
  • End-user systems development any systems
    development project in which the primary effort
    is undertaken by a combination of business
    managers and users
  • End-user-developed systems can be structured as
    complementary to, rather than in conflict with,
    existing and emerging information systems

15
Outsourcing and On Demand Computing
  • An outside consulting firm or computer company
    that specializes in systems development can take
    over some or all of the development and
    operations activities
  • Reasons for using outsourcing and on demand
    computing
  • Reducing costs, obtaining state-of-the-art
    technology, eliminating staffing and personnel
    problems, and increasing technological
    flexibility

16
Use of Computer-Aided Software Engineering (CASE)
Tools
  • Computer-aided software engineering (CASE) tools
    that automate many of the tasks required in a
    systems development effort and encourage
    adherence to the SDLC
  • Instill a high degree of rigor and
    standardization to the entire systems development
    process
  • Upper-CASE tools focus on investigation,
    analysis, and design
  • Lower-CASE tools focus on implementation

17
Object-Oriented Systems Development
  • Object-oriented systems development (OOSD)
    approach to systems development that combines the
    logic of the systems development life cycle with
    the power of object-oriented modeling and
    programming

18
Systems Investigation
  • What primary problems might a new or enhanced
    system solve?
  • What opportunities might a new or enhanced system
    provide?
  • What new hardware, software, databases,
    telecommunications, personnel, or procedures will
    improve an existing system or are required in a
    new system?
  • What are the potential costs (variable and
    fixed)?
  • What are the associated risks?

P 350
19
Initiating Systems Investigation
  • Systems request form document filled out by
    someone who wants the IS department to initiate
    systems investigation
  • Helps rationalize and prioritize the activities
    of the IS department
  • Includes the following information
  • Problems in and opportunities for system
  • Objectives in investigation
  • Overview, costs, and benefits of proposed system

20
Feasibility Analysis
  • Technical feasibility hardware, software, and
    other system components
  • Economic feasibility predicted benefits vs. cost
    and time
  • Legal feasibility limitations of laws and
    regulations on project
  • Operational feasibility logistical and
    motivational considerations
  • Schedule feasibility completion of project in
    reasonable amount of time

21
Object-Oriented Systems Investigation
  • Key objects can be identified during systems
    investigation
  • Use case diagram
  • Part of the Unified Modeling Language (UML) used
    in object-oriented systems development
  • Actors represent persons interacting with system
  • Use cases represent system activity in response
    to an event.

See Sys Anal des pg 221.
22
Object-Oriented Systems Investigation (continued)
Figure 8.8 Use Case Diagram for a Kayak Rental
Application
23
The Systems Investigation Report
  • Systems investigation report
  • Summary of the results of the systems
    investigation and the process of feasibility
    analysis
  • Recommendation of a course of action
  • Continue systems analysis
  • Modify the project
  • Abandon the project
  • Reviewed by steering committee of senior
    management and users

24
Systems Analysis
  • Answers the question What must the information
    system do to solve the problem?
  • Overall emphasis of systems analysis is
  • Gathering data on the existing system
  • Determining the requirements for the new system
  • Considering alternatives within these constraints
  • Investigating the feasibility of the solutions
  • Primary outcome prioritized list of systems
    requirements

25
Data Collection
  • Identifying sources of data
  • Internal sources
  • External sources
  • Collecting data
  • Interviews structured and unstructured
  • Direct observation
  • Questionnaires structured or unstructured
  • Used when data sources are spread over a wide
    geographic area

26
Data Analysis
  • Data analysis
  • Manipulation of collected data so that systems
    development team can use the data
  • Data modeling
  • Entity-relationship (ER) diagrams objects,
    attributes, and associations
  • Activity modeling
  • Data-flow diagrams (DFDs) objects, associations,
    and activities

27
Data Analysis (continued)
Figure 8.12 Data and Activity Modeling (b) A
data-flow diagram
28
Data Flow Diagrams (DFDs)
  • Graphical system model that shows all main
    requirements for an IS in one diagram or set of
    diagrams
  • Inputs/outputs,
  • Processes,
  • Data storage.
  • Easy to read and understand with minimal
    training. Ref San Diego Periodicals.

Slide from ITEC 2010
29
Data Flow Diagram Symbols(Figure 6-3)
Learn !
Slide from ITEC 2010
30
Data Analysis (continued)
Figure 8.12 Data and Activity Modeling (a) An
entity-relationship diagram
31
Data Analysis (continued)
Figure 8.12 Data and Activity Modeling (c) A
semantic description of the business process
32
Customers, Orders, and Order Items
Slide from ITEC 2010
33
ERD with Many-to-Many Relationships
Slide from ITEC 2010
34
Many-to-Many Relationship Converted to
Associative Entity to Store Grade Attribute
Slide from ITEC 2010
35
Requirements Analysis
  • Determines user, stakeholder, and organizational
    needs through the following techniques
  • Asking directly best for stable systems
  • Critical success factors asks for critical
    factors in interviewees area
  • IS plan translates strategic plan into
    initiatives
  • Requirements analysis tools CASE tools

36
Requirements Analysis (continued)
Figure 8.13 Converting Organizational Goals into
Systems Requirements
37
Object-Oriented Systems Analysis
  • Identifying problems or potential opportunities
  • Identifying key participants and collecting data
  • Uses classes and generalization/specialization
    hierarchies instead of data-flow diagrams and
    flowcharts

Be able to recognize a class diagram box.
38
Object-Oriented Systems Analysis (continued)
Figure 8.14 Generalization/Specialization
Hierarchy Diagram for Single and Tandem Kayak
Classes
39
The Systems Analysis Report
  • Systems analysis report should cover
  • Strengths and weaknesses of the existing system
    from a stakeholders perspective
  • User/stakeholder requirements for the new system
    (also called the functional requirements)
  • Organizational requirements for the new system
  • Description of what the new information system
    should do to solve the problem

40
Systems Design
  • Answers the question How will the information
    system solve a problem?
  • Has two dimensions logical and physical
  • Logical design description of the functional
    requirements of a system
  • Physical design specification of the
    characteristics of the system components
    necessary to put the logical design into action

41
Object-Oriented Design
  • Design key objects and classes of objects in the
    new or updated system
  • Consideration of the problem domain, the
    operating environment, and the user interface
  • Consideration of the sequence of events that must
    happen for the system to function correctly
  • Scenario sequence of events
  • Can be diagrammed in a sequence diagram

42
Object-Oriented Design (continued)
Figure 8.16 A Sequence Diagram to Add a New
KayakItem Scenario
43
Generating Systems Design Alternatives
  • Request for proposal (RFP) document that
    specifies in detail required resources such as
    hardware and software
  • Financial options
  • Purchasing
  • Leasing
  • Renting

44
Systems Implementation
Page 364
Figure 8.19 Typical Steps in Systems
Implementation
45
Acquiring Hardware from an IS Vendor
  • IS vendor company that offers hardware,
    software, telecommunications systems, databases,
    IS personnel, and/or other computer-related
    resources
  • Buying computer hardware
  • Leasing computer hardware
  • Renting computer hardware
  • Pay-as-you-go, on-demand, or utility
    computing

46
Data Preparation
  • Also called data conversion
  • Ensures all files and databases are ready to be
    used with new computer software and systems

47
Testing
  • Unit testing testing of individual programs
  • System testing testing the entire system of
    programs
  • Volume testing testing the application with a
    large amount of data
  • Integration testing testing all related systems
    together
  • Acceptance testing conducting any tests required
    by the user

48
Start-Up
  • Process of making the final tested information
    system fully operational
  • Approaches
  • Direct conversion (plunge, direct cutover)
    stopping the old system and starting the new one
    on a given date
  • Phase-in approach (piecemeal) slowly replacing
    old system components with new system components
  • Pilot start-up run new system with one group of
    users
  • Parallel start-up running old and new systems
    together for a period of time

49
User Acceptance
  • User acceptance document formal agreement signed
    by the user that states that a phase of the
    installation or the complete system is approved
  • Legal document that removes or reduces IS
    vendors liability

50
Systems Review
  • Process of analyzing systems to make sure that
    they are operating as intended
  • Often compares the performance and benefits of
    the system as it was designed with the actual
    performance and benefits of the system in
    operation
  • Event-driven review triggered by a problem or
    opportunity such as an error, a corporate merger,
    or a new market for products
  • Time-driven review performed after a specified
    amount of time
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