CHAPTER 14 INFORMATION SYSTMES DEVELOPMENT

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CHAPTER 14INFORMATION SYSTMES DEVELOPMENT
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Learning Objectives

• Discuss the concept of a systems development life
  cycle (SDLC)
• Describe the information systems planning process
• Discuss the advantages and disadvantages of the
  traditional development, prototyping, rapid
  application development, object-oriented
  development, and end-user development life cycles
• Identify the advantages and disadvantages of CASE
  tools
• Evaluate the alternatives to in-house systems
  development
• Discuss the key features of Internet and intranet
  development

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Chapter Overview
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Case Success in Systems Development at
Inland Steel is a Team Effort

• The Business Problem

• The Solution

• reviewed all requests from the business units for
  changes and enhancements, and approved only a
  dozen, to minimize the tendency of a projects
  goals to grow beyond initial specifications
  during the development process

• The Results

• reduce by 50 percent the response time to
  customer inquiries
• upgraded and expanded some jobs from clerical to
  professional functions
• integrating information in an IBM DB2 relational
  database that previously had resided in isolated
  databases

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Case (continued)

• What have we learned from this case??

• Information systems timely and careful
  development is a very high priority
• Many firms no longer attempt a major systems
  development by themselves

• System development is a team effort that often
  includes end users, top management, IS
  professional, vendors, consultants, and whatever
  other specialized expertise is necessary

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Information Systems Planning
IS Planning Process
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IS Planning (continued )

• The IS Strategic Plan
• Objectives
• it must be aligned with the organizations
  strategic plan
• it must provide for an IT architecture that
  enables users, applications, and databases to be
  seamlessly networked and integrated
• it must efficiently allocate IS development
  resources among competing projects, so the
  projects can be completed on time, within budget,
  and have required the functionality
• Issues efficiency effectiveness
  competitiveness

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IS Planning (continued )

• The IS Operational Plan
• Mission the mission of the IS function
• IS environment the summary of the information
  needs of the functional areas and of the
  organization as a whole
• Objectives of the IS function the IS functions
  current best estimate of its goals
• Constraints on the IS function technological,
  financial, and personnel limitations on the IS
  function
• Long-term systems need a summary of the
  processes needed by a company and the IS projects
  selected to support them and reach organizational
  goals
• Short-range plan an inventory of current
  projects, and a detailed plan of projects to be
  developed or continued during the current year

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The Traditional Systems Development Life Cycle
(SDLC)

• SDLC - the development method used by most
  organizations today for large, complex systems
• Waterfall Approach - a sequence of steps in the
  SDLC with cycles returned to previous stops
• Systems Analysts - IS professionals who
  specialize in analyzing and designing information
  systems
• Programmers - IS professionals who modify
  existing computer programs or write new computer
  programs to satisfy user requirements
• Technical Specialists - experts in a certain type
  of technology, such as databases or
  telecommunications

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SDLC (continued )
An eight-stage systems development life cycle
(SDLC)
(1) Systems Investigation
(2) Systems Analysis
(3) Systems Design
(4) Programming
(5) Testing
(6) Implementation
(7) Operation
(8) Maintenance
Go Back to a previous Stage or Stop
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SDLC (continued )

• Systems Investigation (Step 1)
• Feasibility Study determines the probability of
  success of proposed systems development project
  and assesses the projects
• technical feasibility determines if the
  hardware, software, and communication components
  can be developed or acquired to solve the
  business problem
• economic feasibility determines if the project
  is an acceptable financial risk and if the
  organization can afford the expense and time
  needed to complete the project
• behavioral feasibility addresses the human
  issues of the project

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SDLC (continued )

• Systems Analysis (Step 2)
• the examination of the business problem that the
  organization plans to solve with information
  systems
• produces the following information
• strengths and weaknesses of the existing system
• functions that the new systems must have to solve
  the business problem
• user information requirements for the new systems

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SDLC (continued )

• Systems Design (Step 3)
• describes how the system will accomplish the task
  
• technical design
• system outputs, inputs, and user interfaces
• hardware, software, databases, telecommunications,
  personnel, and procedures
• how these components are integrated
• local systems design what the system will do
• Physical systems design how the system will
  perform its functions

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SDLC (continued )

• Programming (Step 4)
• the translation of the design specifications into
  computer code
• structured programming techniques improve the
  logical flow of the program by decomposing the
  computer code into modules, which are sections of
  code
• sequence structure
• decision structure
• loop structure

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SDLC (continued )

• Testing (Step 5)
• checks to see if the computer code will produce
  the expected and desired results under certain
  conditions
• syntax errors misspelled word or a misplaced
  comma
• logic errors permit the program to run, but
  result in incorrect output

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SDLC (continued )

• Implementation (Step 6)
• the process of converting from the old system to
  the new system
• four major conversion strategies
• parallel conversion the old and new systems
  operate simultaneously for a period of time
• direct conversion the old system is cut off and
  the new systems is turned on at a certain point
  in time
• pilot conversion introduces the new system in
  one part of the organization
• phased conversion introduces components of the
  new systems in stages

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SDLC (continued )

• Operation (Step 7)
• the new systems will operate for a period of
  time, until it no longer meets its objectives
• Maintenance (Step 8)
• debugging the program
• updating the system to accommodate changes in
  business conditions
• add new functionality to the system

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Prototyping

• Prototyping obtain only a general idea of user
  requirements
• Advantages
• speeds up the development approach
• gives the users the opportunity to clarify their
  information requirements
• useful in the development of decision support
  systems and executive information systems
• Disadvantages
• replaces the systematic analysis and design
  stages of the SDLC - quality may be sacrificed
• can result in an excess of iterations

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Joint Application Design (JAD)

• JAD is a group-based method for collecting user
  requirements and creating staged designs
• Advantages
• saves time
• greater support for, and acceptance of new
  systems
• produces higher quality systems
• easier implementation
• lower training costs
• Disadvantages
• very difficult to get all users to JASD meetings
• all the problems that may be caused by any group
  process

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Rapid Application Development (RAD)

• RAD is a systems development method that can
  combine JAD, prototyping, and integrated CASE
  tools, to rapidly produce a high-quality system
• Advantages
• active involvement of users in the development
  process
• speeds the development process
• reduces development costs
• can create applications that are easier to
  maintain and modify
• Disadvantages
• may result in systems with limited functionality
  and adaptability for change

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Integrated Computer-Assisted Software Engineering
(ICASE) Tools

• ICASE Tools automate many of the tasks in the
  SDLC
• Upper CASE, lower CASE and integrated CASE
• Advantages
• produces systems with a longer effective
  operational life
• speeds up the development process and result in
  systems that are more flexible and adaptable to
  changing business conditions
• results in excellent documentation
• Disadvantages
• more expensive to build and maintain initial
  system
• requires more extensive and accurate definition
  of user needs and requirements
• difficult to customize and may be difficult to
  use with existing system

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Object-Oriented Development

• Object-Oriented Development based on a
  fundamentally different view of computer systems
  than that found in traditional SDLC development
  approaches
• Advantages
• reduces the complexity of systems development and
  leads to systems that are easier and quicker to
  build an maintain
• improves programmers productivity and quality
• more flexible
• allows systems analysts to think the real-world
  systems
• ideal for developing Web applications
• depicts the various elements of an information
  systems in user standing of what the new system
  does and how it meets its objectives
• Disadvantages
• runs more slowly
• needs to retain the programmers

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Systems Development outside the IS Department

• End-User Development
• users will continue to do more ad hoc programming
• Types of end-user computing
• non programming end users enter data, use
  applications
• command-level users access data, print reports
• end-user programmers develop applications for
  personal use
• functional support personnel develop
  applications for others to use
• end-user computing support personnel training,
  hotline, help users develop applications
• programmers develop complex applications

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Systems Development outside the IS Department
(continues )

• End-User Development (CONT)
• Factors that drive the trends toward increased
  end-user computing and end-user development
• increasingly powerful desktop hardware
• declining hardware costs
• increase diverse software capabilities
• increasingly computer literate population
• backlog of IS projects
• development speed

• business orientation

• small applications

• control

• Apparent cost savings

• User friendly software

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Systems Development outside the IS Department
(continues )

• Advantages of End-User Development
• gives users control over both the initial
  development of an application and the ongoing
  maintenance
• no need to explain user requirements to IS
  analysts
• gives users control over the development budget
• results in the possibility of greater user
  acceptance
• Disadvantages of End-User Development
• needs some additional spending
• difficult for managers outside the IS area to
  evaluate end-user development activities
• fail to produce adequate documentation for the
  systems
• security may be breached

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Systems Development outside the IS Department
(continues )

• External Acquisition of Software
• factors considered during make-or-buy decision
• on-time
• on-budget
• full functionality
• user acceptance
• favorable costs-to-benefits ratio
• low maintenance
• scalability
• integration with other systems
• minimal negative cross-impacts
• reusability

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Systems Development outside the IS Department
(continues )

• Outsourcing
• purchase of any product or service from other
  company

• advantages
• economies of scale of hardware
• economies of scale of staffing
• specialization
• tax benefits

• Disadvantages
• limited economies of scale
• staffing
• lack of business expertise
• contract problems
• internal cost reduction opportunities

• guidelines
• write short-period contracts
• subcontracting
• selective outsourcing

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Building Internet andIntranet Applications

• An Internet and intranet Development Strategy
• identify the objectives for organizational Web
  site(s) and pages
• adequately cover infrastructure requirements as
  well as security are legal issues
• identify and prioritize potential projects

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Internet and Intranet

• JAVA - A Promising Tools
• the most important programming language for
  putting extra features into Web pages
• an object-oriented language
• can be sent from a Web server over the Internet
  and then run on the computer that is viewing the
  Web page
• has numerous security features to prevent
  downloaded programs from damaging files or
  creating other problems on the receiving computer

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Whats in IT for Me?

• For Accounting
• accounting functions are traditionally
  data-intensive
• properly developed systems are a must
• For Finance
• those acquainted with systems development
  methodologies are better equipped to assist in
  getting the right systems developed in the right
  way and budget
• For Marketing
• marketing functions are hotbed of systems
  development

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Whats in IT for Me? (continued )

• For Production/Operations Management
• increasingly computer-controlled and integrated
  with other allied systems, from design to
  logistics to inventory control to production
  planning
• For Human Resources Management
• new systems may require terminating employees,
  hiring new employees, or changing job descriptions