Fundamentals of Information Systems Fourth Edition

1
Fundamentals of Information SystemsFourth Edition

• Chapter 8
• Systems Development

2
Principles and Learning Objectives

• Effective systems development requires a team
  effort of stakeholders, users, managers, systems
  development specialists, and various support
  personnel, and it starts with careful planning
• Identify the key participants in the systems
  development process and discuss their roles
• Define the term information systems planning and
  discuss the importance of planning a project

3
Principles and Learning Objectives (continued)

• Systems development often uses different
  approaches and tools such as traditional
  development, prototyping, rapid application
  development, end-user development, computer-aided
  software engineering, and object-oriented
  development to select, implement, and monitor
  projects
• Discuss the key features, advantages, and
  disadvantages of the traditional, prototyping,
  rapid application development, and end-user
  systems development life cycles

4
Principles and Learning Objectives (continued)

• Systems development often uses different
  approaches and tools such as traditional
  development, prototyping, rapid application
  development, end-user development, computer-aided
  software engineering, and object-oriented
  development to select, implement, and monitor
  projects (continued)
• Discuss the use of computer-aided software
  engineering (CASE) tools and the object-oriented
  approach to systems development

5
Principles and Learning Objectives (continued)

• Systems development starts with investigation and
  analysis of existing systems
• State the purpose of systems investigation
• State the purpose of systems analysis and discuss
  some of the tools and techniques used in this
  phase of systems development

6
Principles and Learning Objectives (continued)

• Designing new systems or modifying existing ones
  should always be aimed at helping an organization
  achieve its goals
• State the purpose of systems design and discuss
  the differences between logical and physical
  systems design
• Define the term RFP and discuss how this document
  is used to drive the acquisition of hardware and
  software

7
Principles and Learning Objectives (continued)

• The primary emphasis of systems implementation is
  to make sure that the right information is
  delivered to the right person in the right format
  at the right time
• State the purpose of systems implementation and
  discuss the various activities associated with
  this phase of systems development

8
Principles and Learning Objectives (continued)

• Maintenance and review add to the useful life of
  a system but can consume large amounts of
  resources, so they benefit from the same rigorous
  methods and project management techniques applied
  to systems development
• State the importance of systems and software
  maintenance and discuss the activities involved
• Describe the systems review process

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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

10
An Overview of Systems Development

• Managers and employees in all functional areas
  work together in a business information system
• Users help and often lead the way with
  development process
• Participants in systems development
• Determine when a project fails
• Are critical to systems development success

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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

12
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

13
Information Systems Planning and Aligning
Corporate and IS Goals (continued)
Figure 8.2 Information Systems Planning
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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

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The Traditional Systems Development Life Cycle
Figure 8.3 The Traditional Systems Development
Life Cycle
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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?

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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

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Prototyping

• An iterative approach to systems development

Figure 8.4 Prototyping
19
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

20
Rapid Application Development, Agile Development,
Joint Application Development, and Other Systems
Development Approaches (continued)

• Joint application development (JAD)
• Process for data collection and requirements
  analysis in which users, stakeholders, and IS
  professionals work together to analyze existing
  systems, propose possible solutions, and define
  the requirements of a new or modified system
• Used extensively by RAD
• Often utilizes group support systems (GSS)
  software to foster positive group interactions

21
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

22
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

23
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

24
Use of Computer-Aided Software Engineering (CASE)
Tools (continued)
Table 8.2 Advantages and Disadvantages of CASE
Tools
25
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

26
Object-Oriented Systems Development (continued)

• Object-oriented systems development typically
  involves
• Identifying potential problems and opportunities
  within the organization that would be appropriate
  for the OO approach
• Defining the kind of system users require
• Designing the system
• Programming or modifying modules
• Evaluation by users
• Periodic review and modification

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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?

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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

29
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

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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 objects
• Use cases represent events

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Object-Oriented Systems Investigation (continued)
Figure 8.8 Use Case Diagram for a Kayak Rental
Application
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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

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The Systems Investigation Report (continued)
Figure 8.9 A Typical Table of Contents for a
Systems Investigation Report
34
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

35
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

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Data Collection (continued)
Figure 8.10 Internal and External Sources of
Data for Systems Analysis
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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

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Data Analysis (continued)
Figure 8.12 Data and Activity Modeling (a) An
entity-relationship diagram
39
Data Analysis (continued)
Figure 8.12 Data and Activity Modeling (b) A
data-flow diagram
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Data Analysis (continued)
Figure 8.12 Data and Activity Modeling (c) A
semantic description of the business process
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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

42
Requirements Analysis (continued)
Figure 8.13 Converting Organizational Goals into
Systems Requirements
43
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

44
Object-Oriented Systems Analysis (continued)
Figure 8.14 Generalization/Specialization
Hierarchy Diagram for Single and Tandem Kayak
Classes
45
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

46
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

47
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

48
Object-Oriented Design (continued)
Figure 8.16 A Sequence Diagram to Add a New
KayakItem Scenario
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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

50
Generating Systems Design Alternatives (continued)

• Evaluating and Selecting a Systems Design
• Preliminary evaluation
• To dismiss unwanted proposals
• Begins after all proposals have been submitted
• Final evaluation
• Detailed investigation of the proposals offered
  by the vendors remaining after the preliminary
  evaluation

51
The Design Report

• Design report primary result of systems design,
  reflecting the decisions made and preparing the
  way for systems implementation
• System specifications include technical
  description of the following
• System outputs, inputs, and user interfaces
• Hardware, software, databases, telecommunications,
  personnel, and procedure components and the way
  these components are related

52
The Design Report (continued)
Figure 8.18 A Typical Table of Contents for a
Systems Design Report
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Systems Implementation
Figure 8.19 Typical Steps in Systems
Implementation
54
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

55
Acquiring Software Make or Buy?

• Make-or-buy decision decision regarding whether
  to obtain software from external or internal
  sources
• Choices include
• Purchase software externally
• Develop software in-house
• Used a blend of external and internal software
  development
• Rent software

56
Acquiring Database and Telecommunications Systems

• Databases and telecommunications systems require
  a blend of hardware and software
• New hardware is acquired from an IS vendor
• New or upgraded software might be purchased or
  developed in-house

57
User Preparation

• Process of readying managers, decision makers,
  employees, other users, and stakeholders for new
  systems
• Provide users with proper training

58
IS Personnel Hiring and Training

• Personnel that might be needed for the new system
• IS manager
• Systems analysts
• Computer programmers
• Data-entry operators
• Training programs should be conducted for the IS
  personnel who will be using the computer system

59
Site Preparation

• Preparation of the location of a new system
• Making room for equipment
• Special wiring and air conditioning
• Special floor
• Security system
• Additional power circuits

60
Data Preparation

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

61
Installation

• Physically placing the computer equipment on the
  site and making it operational
• Normally the manufacturer is responsible for
  installing computer equipment
• Someone from the organization (usually the IS
  manager) should oversee the process

62
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

63
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

64
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

65
Systems Operation and Maintenance

• Systems operation use of a new or modified
  system
• Help desk provides support
• Systems maintenance checking, changing, and
  enhancing the system to make it more useful in
  achieving user and organizational goals
• Difficult and costly for legacy systems

66
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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Systems Review (continued)
Table 8.4 Examples of Review Types
68
Summary

• Information systems planning translating
  strategic and organizational goals into systems
  development initiatives
• Common systems development life cycles
  traditional, prototyping, rapid application
  development (RAD), and end-user development
• Phases of traditional systems development life
  cycle systems investigation, systems analysis,
  systems design, systems implementation, and
  systems maintenance and review

69
Summary (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 defines how the information
  system will do what it must do to obtain the
  problem solution

70
Summary (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 that the
  system operates as intended and modifies the
  system so that it continues to meet changing
  business needs