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AIS Development Strategies

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Computer-Aided Software Engineering (CASE) Tools ... Described what computer-aided software engineering is and how it's used in systems development. ... – PowerPoint PPT presentation

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Title: AIS Development Strategies


1
AIS Development Strategies
  • Chapter 19

2
METHODS FOR OBTAINING A NEW INFORMATION SYSTEM
  • Purchasing prewritten software
  • Developing software in-house
  • Outsourcing

3
PURCHASING PREWRITTEN SOFTWARE
  • Canned software is sold on the open market to a
    broad range of users with similar requirements.
  • Turnkey systems - hardware and software sold
    together as a package.
  • Disadvantages
  • Inflexibility
  • May not meet all of the companys needs

4
PURCHASING PREWRITTEN SOFTWARE
  • Application service providers (ASPs).
  • ASPs host web-based software and deliver it to
    clients over the Internet.
  • Companies dont have to buy, install, or maintain
    canned software they simply rent it.
  • Advantages of ASPs
  • Reduction of software costs and administrative
    overhead.
  • Automated software upgrades.
  • Scalability as the business grows.
  • Global access to information.
  • Access to skilled IT personnel.
  • Ability to focus on core financial competencies
    rather than IT.

5
PURCHASING PREWRITTEN SOFTWARE
  • Purchasing Software and the SDLC
  • SDLC is still followed for purchased software
  • Systems analysis
  • Conceptual design
  • Physical design
  • Implementation and conversion
  • Operation and maintenance

6
PURCHASING PREWRITTEN SOFTWARE
  • Acquiring Hardware and Software
  • Request for proposal (RFP) - invitation to
    bidders to propose a system by a specific date.
  • Each proposal is evaluated.
  • Finalists are investigated in depth.
  • Advantages
  • Saves time
  • Simplifies the decision-making process
  • Reduces errors
  • Avoids potential for disagreement

7
PURCHASING PREWRITTEN SOFTWARE
  • Evaluating Proposals and Selecting a System
  • Eliminate any proposals that
  • Are missing important information.
  • Fail to meet minimum requirements.
  • Are ambiguous.
  • Those that pass the preliminary screening should
    be compared with the proposed AIS requirements to
    determine
  • If they meet all mandatory requirements.
  • How many desirable requirements they meet.

8
PURCHASING PREWRITTEN SOFTWARE
  • Criteria to evaluate hardware include
  • Cost
  • Ability to run required software
  • Processing speed and capabilities
  • Secondary storage capability
  • Input and output speeds
  • Communication capabilities
  • Expandability
  • Recency of technology
  • Availability
  • Compatibility with existing hardware, software,
    and peripherals
  • Performance compared to competitors
  • Cost and availability of support and maintenance
  • Warrantees and guarantees
  • Financing arrangements
  • Ability to meet mandatory requirements

9
PURCHASING PREWRITTEN SOFTWARE
  • Criteria to evaluate software include
  • Conformity with specifications
  • Need for modification
  • Performance (speed, accuracy, reliability)
  • Use by other companies
  • Satisfaction of other users
  • Documentation
  • Compatibility with existing software
  • User-friendliness
  • Ability to be demonstrated and test-driven
  • Warranties
  • Flexibility and maintainability
  • Capability for online inquiry of files and
    records
  • Vendor upgrades

10
PURCHASING PREWRITTEN SOFTWARE
  • Criteria to evaluate vendors include
  • Size
  • Financial stability and security
  • Experience
  • Quality of support and warranties
  • Regularity of updates
  • Ability to provide financing
  • Willingness to sign contract
  • Willingness to provide references
  • Reputation for reliability and dependability
  • Hardware and software support and maintenance
  • Implementation and installation support
  • Quality and responsiveness of personnel
  • Willingness to provide training
  • Responsiveness and timeliness of support

11
PURCHASING PREWRITTEN SOFTWARE
  • Approaches to comparing system performance
  • Benchmark problem
  • Point scoring
  • Requirements costing

12
PURCHASING PREWRITTEN SOFTWARE
  • EXAMPLE
  • Zorba Co. is evaluating systems offered by three
    different vendors Able Co., Baker Co., and Cook
    Co.
  • Zorba has determined three criteria that they
    will use to evaluate the different systems
    cost, speed, and vendor reliability.
  • They have provided the following weights to each
    criteria, with vendor reliability being the most
    critical
  • Vendor reliability9
  • Cost6
  • Speed4

13
PURCHASING PREWRITTEN SOFTWARE
  • Zorba examined the packages offered by the three
    vendors and rated them based on these three
    criteria. Ratings were from 1-5 with 5 being the
    highest score.

14
PURCHASING PREWRITTEN SOFTWARE
  • The weighted scores are then computed by
    multiplying the rating given to each vendor on
    each criterion times the weight assigned to that
    criterion.

X

15
PURCHASING PREWRITTEN SOFTWARE
  • The weighted scores for each company are summed
  • Able 60 points
  • Baker 79 points
  • Cook 68 points
  • Based on the preceding scores, the bid would
    probably be awarded to Baker Co.

16
PURCHASING PREWRITTEN SOFTWARE
  • Approaches to comparing system performance
  • Benchmark problem
  • Point scoring
  • Requirements costing

17
DEVELOPING SOFTWARE IN-HOUSE
  • Reasons
  • Their requirements are unique or
  • Their size and complexity necessitates a custom
    package.
  • Disadvantages
  • Lack of time.
  • Complexity of desired system.
  • Poor requirements and systems planning.
  • Inadequate communication and cooperation between
    departments and users.
  • Lack of qualified staff.
  • Poor senior executive support.

18
DEVELOPING SOFTWARE IN-HOUSE
  • Control the development process and observe the
    following guidelines
  • Carefully select a developer
  • Sign a contract to clearly define
    responsibilities
  • Plan and monitor each step
  • Maintain effective and frequent communication
  • Control all costs

19
DEVELOPING SOFTWARE IN-HOUSE
  • End-User Developed Software
  • Hands-on development, use, and control of
    computer-based information systems by users
  • Allows individuals use IT to meet their own IS
    needs rather than rely on systems professionals
  • Factors contributing to EUC are
  • Increased computer literacy.
  • Easier-to-use programming languages.
  • Inexpensive PCs.
  • A variety of powerful and inexpensive software
    packages.

20
DEVELOPING SOFTWARE IN-HOUSE
  • EUCs allows users to develop their own systems
    to
  • Create and store data.
  • Access and download company data.
  • Share data and computer resources in networks.

21
DEVELOPING SOFTWARE IN-HOUSE
  • EUD may be most appropriate for tasks such as
  • Querying company databases to produce simple
    reports
  • Performing what if, sensitivity or other
    statistical analyses
  • Developing applications for prewritten software
  • Preparing schedules and lists

22
DEVELOPING SOFTWARE IN-HOUSE
  • Benefits of end-user computing
  • User creation, control, and implementation
  • Systems that meet user needs
  • Timeliness
  • Freeing up systems resources
  • Versatility and ease of use

23
DEVELOPING SOFTWARE IN-HOUSE
  • Risks of end-user computing
  • Logic and development errors
  • Inadequately tested applications
  • Inefficient systems
  • Poorly controlled and documented systems
  • System incompatibilities
  • Duplication of systems and data and wasted
    resources
  • Increased costs

24
OUTSOURCE THE SYSTEM
  • Outsourcing is hiring an outside company to
    handle all or part of an organizations data
    processing activities.
  • Examples of outsourced activities
  • Installation
  • Training
  • Maintenance
  • Help desk
  • Technical support

25
OUTSOURCE THE SYSTEM
  • Multiple companies are used in order to
  • Increase flexibility
  • Increase competition
  • Reduce costs
  • Activities that are not outsourced
  • Strategic management of their IT environment
  • Business process management
  • IT architecture

26
OUTSOURCE THE SYSTEM
  • Benefits of outsourcing
  • Provides a business solution
  • Asset utilization
  • Access to greater experience and more advanced
    technology
  • Lower costs
  • Improved development time
  • Elimination of peaks-and-valleys usage
  • Facilitation of downsizing

27
OUTSOURCE THE SYSTEM
  • Risks of outsourcing
  • Inflexibility
  • Loss of control
  • Reduced competitive advantage
  • Locked in system
  • Unfulfilled goals
  • Poor service

28
METHODS FOR IMPROVING THE DEVELOPMENT PROCESS
  • Business process reengineering
  • Prototyping
  • Computer-aided software engineering (CASE) tools

29
BUSINESS PROCESS REENGINEERING
  • Business process reengineering (BPR) is the
    analysis and redesign of business processes and
    information systems to achieve significant
    performance improvements.
  • Reduces a company to its essential business
    processes
  • Reshapes organizational work practices and
    information flows to take advantage of
    technological advancements.

30
BUSINESS PROCESS REENGINEERING
  • Michael Hammers principles for reengineering
    business processes
  • Organize around outcomes, not tasks.
  • Require those who use the output to perform the
    process.
  • Require those who produce information to process
    it.
  • Centralize AND disperse data.
  • Integrate parallel activities.
  • Empower workers, use built-in controls, and
    flatten the organization chart.
  • Capture data onceat its source.

31
BUSINESS PROCESS REENGINEERING
  • Challenges Faced by Reengineering Efforts
  • Tradition
  • Resistance
  • Time and cost requirements
  • Lack of management support
  • Skepticism
  • Retraining
  • Controls

32
PROTOTYPING
  • Prototyping is an iterative approach to systems
    design in which a simplified working model of a
    system is developed.
  • Developers who use prototyping still go through
    the systems development life cycle.

33
PROTOTYPING
  • Four steps are involved in developing a
    prototype
  • STEP ONE Identify basic requirements
  • STEP TWO Develop an initial prototype
  • STEP THREE Repeated iterations
  • STEP FOUR Use the system

34
PROTOTYPING
  • Changes may be necessary to allow the program to
  • Accept real input.
  • Access real data files.
  • Process data.
  • Make necessary computations and calculations.
  • Produce real output.

35
PROTOTYPING
  • When to Use Prototyping
  • Users dont fully understand their needs, or the
    needs change rapidly
  • System requirements are difficult to define
  • System inputs and outputs are not known
  • The task to be performed is unstructured or
    semi-structured
  • Designers are uncertain about what technology to
    use
  • The system is crucial and needed quickly
  • The risk of developing the wrong system is high
  • The users reactions to the new system are
    important development considerations
  • Many design strategies must be tested
  • The design staff has little experience developing
    this type of system or application
  • The system will be used infrequently so that
    processing efficiency is not crucial

36
PROTOTYPING
  • Advantages of Prototyping
  • Better definition of user needs
  • Higher user involvement and satisfaction
  • Faster development time
  • Fewer errors
  • More opportunity for changes
  • Less costly

37
PROTOTYPING
  • Disadvantages of Prototyping
  • Significant user time
  • Less efficient use of system resources
  • Incomplete system development
  • Inadequately tested and documented systems
  • Negative behavioral reactions
  • Never-ending development

38
Computer-Aided Software Engineering (CASE) Tools
  • Computer-aided software (or systems) engineering
    (CASE) tools are an integrated package of
    computer-based tools that automate important
    aspects of the software development process.
  • Used to plan, analyze, design, program, and
    maintain an information system

39
Computer-Aided Software Engineering (CASE) Tools
  • Advantages of CASE technology
  • Increased productivity
  • Improved program quality
  • Cost savings
  • Improved control procedures
  • Simplified documentation

40
Computer-Aided Software Engineering (CASE) Tools
  • Problems with CASE technology
  • Incompatibility
  • Cost
  • Unmet expectations

41
SUMMARY
  • We have
  • Discussed how organizations buy software,
    hardware, and vendor services.
  • Explained how information systems departments
    develop custom software.
  • Identified how end users develop, use and control
    computer-based information systems.
  • Explained why organizations outsource their
    information systems, as well as the benefits and
    risks of doing so.
  • Discussed what reengineering processes entail and
    when they are appropriate.
  • Explained how prototypes are used to develop an
    AIS and when it is advantageous to do so.
  • Described what computer-aided software
    engineering is and how its used in systems
    development.
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