Ch. 12 Systems Investigation and Analysis

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Ch. 12 Systems Investigation and Analysis

• Overview of Systems Development
• Systems Development Lifecycles
• Factors Affecting Systems Development Success
• Systems Investigation
• Systems Analysis

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Systems Development

• The process of transforming organizational
  problems or opportunities into information
  technology enabled solutions
• Participants in Systems Development
• Stakeholders people who in some way will benefit
  from the systems development project.
• Users who will interact regularly with the system
• Systems development specialists programmers and
  analysts who are responsible for creating the
  system
• Support personnel

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Information Systems Planning

• The IS plan is developed to support and carry out
  the firms strategic plan.
• The steps of IS planning
• Develop overall objectives
• Identify IS projects
• Set priorities and select projects
• Analyze resource requirements
• Set schedules and deadlines
• Develop IS planning document

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IS Planning

• Developing a Competitive Advantage
• Creative analysis the investigation of new
  approaches to existing problems
• Critical analysis unbiased and careful
  questioning of whether system elements are
  related in the most effective and efficient ways.
  
• Establishing objectives for Systems Development
• Performance objectives
• Output quality or usefulness
• Speed at which output is produced
• Cost objectives
• Development costs
• Fixed investments
• Ongoing operating costs
• Uniqueness costs

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Systems Development Life Cycles

• the systems development process
• Four common systems development life cycles
• Traditional
• Prototyping
• Rapid application development
• End-user development

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Traditional systems development life cycle

• Systems investigation
• The problem is identified and studied to
  determine whether an information system is part
  of the solution
• Systems analysis
• Describes what the information system must do to
  solve the problem
• Systems design
• Determine how the information system will work to
  do what it is required to do
• Systems implementation
• Creating or acquiring all the components
  specified in the design and putting into
  operation
• Systems maintenance and review
• Evaluate results and ensure that the system works
  correctly

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Traditional systems development life cycle

• Advantages
• Management has a large degree of control through
  formal reviews
• Documentation is created which can help in later
  modification of the system
• The method also ensures that system requirements
  are related to a business need
• Disadvantages
• A user does not know the solution until the
  system is finished. The system may not perform as
  expected by the user
• inflexible, regarding changes to user
  requirements discovered during development.

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Prototyping

• an iterative approach to systems development.
• starts with the development of a preliminary
  model of part of the system, such as a
  scaled-down version of the whole system.
• Advantages
• Prototypes can be constructed and operational in
  weeks. Users can provide feedback during systems
  development
• Early error and omission detection
• Disadvantages
• Incomplete or absent documentation

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Fig 12.8
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Types of Prototypes

• An operational prototype accesses real data
  files, edits input data, does calculations, and
  produces output, but usually doesnt update the
  data files.
• A nonoperational prototype is a model that
  includes input screens and printed reports.
  Using a nonoperational prototype shows the user
  how data is captured, the commands that are
  entered, how the system acts, and what reports
  look like, but not all the processing activities.

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Rapid Application Development

• uses tools, techniques, and methods to speed
  application development.
• RAD facilitates user participation in development
  activities, automates code production, and
  reduces paper-based documentation.
• RAD relies on joint application development
  (JAD). JAD involves meetings of users,
  stakeholders, and IS professionals who work
  together to investigate problems, discuss
  solutions, and define the requirements of a new
  or modified system.
• Large systems are split into subsystems so they
  can be quickly finished

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End-User Systems Development

• End users develop systems ranging from small
  systems intended only for personal use
• IS professionals provide technical assistance,
  guidance, and expertise.
• Advantages
• Systems are sometimes developed more quickly
  since end-users believe they have solid knowledge
  of their own needs
• Disadvantages
• Many systems fail due to lack of expertise and
  may not integrate well with other organizational
  computing applications.

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Factors affecting systems development success

• Degree of change the new system brings
• Will the entire system be reengineered and
  everyone retrained?
• Will continuous improvement keep systems up to
  date?
• Will this cost produce many possible benefits?
• How is change going to be managed to keep
  potential problems under control?
• Quality of project planning required for an one
  time, within budget, efficient, and effective
  system

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Use of Project Management Tools

• Project management
• Project schedule
• Project milestone
• Project deadline
• Critical path
• Program Evaluation and Review Technique (PERT) A
  formalized approach for developing a project
  schedule
• Gantt Chart a graphical tool used for planning,
  monitoring, and coordinating projects

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Fig 12.10
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• Use of formal quality assurance processes
• Total quality management and statistical process
  control help ensure a quality systems.
• Use of Computer-Aided Software Engineering (CASE)
  Tools
• Upper-CASE tools address activities in the first
  part of software development, such as
  investigation, analysis, and design
• Lower-CASE tools focus on activities late in
  development, such as code generation
• Integrated-CASE (I-CASE) tools
• Most CASE tools allow multiple people to work on
  the same system at the same time. System objects
  are stored in the CASE repository, which is
  similar to a database in function. This allows
  team members to share information about the
  design and increases management visibility of the
  project.

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System Investigation

• Determine the opportunities and problems that
  face a firm and then decide how to handle them.
• Initiating systems investigation
• Systems request form
• Participants in systems investigation
• Members are responsible for gathering and
  analyzing data, preparing the report used to
  justify the systems development project, and
  presenting the results to top-level management.
• Feasibility Analysis
• Numerous ways to assess whether a project can be
  done.
• The systems Investigation Report
• The main output of the systems investigation
  stage, which is reviewed by senior management, a
  steering committee

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Feasibility Analysis

• Technical feasibility
• asks whether the hardware, software, and other
  technologies needed for the project exist in the
  organization or can be acquired or developed.
• Operational feasibility
• addresses whether this project can be done here,
  in this organization, at this time.
• Schedule feasibility
• determines whether the project can be completed
  in a reasonable amount of time, subject to all
  resource constraints
• Economic feasibility
• determines whether the benefits of the proposed
  system outweigh the costs.
• Legal feasibility
• identifies laws or regulations that may prevent,
  or limit the project or that may require it to be
  done or to be done in a certain way.

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Systems Analysis

• Analysis team IS and functional area staff and
  managers
• Study existing systems, determines requirements
  for the new system, and evaluates alternative
  solutions.
• Key activities data analysis and requirements
  analysis
• Main output a description of systems
  requirements in order of their priority

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Data collection

• Sources of data for Systems Analysis
• Internal and external sources people, documents,
  and organizations
• Methods of data collection
• Interviewing
• observation
• Questionnaire distribution
• sampling

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Data Analysis

• Data modeling
• models objects and relationships using text and
  graphics
• Activity modeling
• is used to model data and its changes as it moves
  through the business process, typically using a
  data-flow diagram, or DFD.
• Application flowcharts
• Grid charts
• show the relationship between 2 aspects of the
  system.
• CASE tools
• provide functionality to do screen and report
  prototyping for end users.

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Fig 12.15
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Fig 12.16
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Fig 12.17
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Requirements Analysis

• Asking directly
• Critical success factors (CSFs)
• The IS plan
• Screen report layout

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Systems Analysis Report

• The main deliverable of systems analysis
• Contents
• the strengths and weaknesses of the existing
  system from a stakeholders point of view
• the functional requirements for the new system
  that is, user or stakeholder requirements the
  organizational requirements for the new system
  and
• a description of what the new information system
  should do.
• This report gives senior management or the
  steering committee a good idea of what can be
  expected of the new system.