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Introduction to System Analysis and Design (Definition of System


System Analysis and Design Introduction to System Analysis and Design (Definition of System & information system components) - Dr. Mahmoud Abu-Arra – PowerPoint PPT presentation

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Title: Introduction to System Analysis and Design (Definition of System

Introduction to System Analysis and
Design(Definition of System information system
System Analysis and Design
  • - Dr. Mahmoud Abu-Arra
  • - Mr. Ahmad Al-Ghoul

learning Objectives
  • Describe the characteristics of system
  • Define an information system and describe its

  • Before talking about the characteristics of
    systems, and information system components let us
    have a historical view for the system analysis
    and design.
  • The analysis and design of a computer based
    information systems began in the 1950s.
  • Since then, the development environment has
    changed dramatically, driven by organizational
    needs as well as by rapid changes in the
    technological capabilities of computers
  • In the 1950s, development focused on the
    processes the software performed
  • Computer power was critical resource, efficiency
    of processing become the major goal
  • Computer were large, expensive, and not very
  • All applications had to be developed in machine
    language or assembly language
  • Software had to be developed from scratch,
    because there was no software industry

  • second step 1960s
  • The second step begins with the first procedural,
    or third generation, computer programming
    languages in the beginning of 1960s
  • Computers were still expensive and large but it
    gets more smaller and faster, less expensive than
  • With the third generation programming languages,
    software industry begins, but most organizations
    still developed their applications from scratch
    using their in-house development staff

  • Third step 1970s
  • Organizations began to realize how expensive it
    was to develop customized information systems for
    every application
  • early database management systems, using
    hierarchal and network models helped storage and
    retrieval of data
  • The development of database management systems
    helped shift the focus of systems development
    from processes first to data first

  • Fourth step 1980s
  • Microcomputers become key organizational tools
  • The software industry expanded greatly as more
    and more people began to write off-the-shelf
    software for microcomputers
  • Developers began to write more and more
    applications in fourth generation languages,
    which unlike procedural languages, instructed a
    computer on what to do instead of how to do it
  • Computer-aided software engineering (CASE) tools
    were developed to make systems developers work
  • A computer get smaller, faster, and cheaper
  • The operating systems for computers moved away
    from line prompt interface to windows and icon
    based interfaces
  • Organizations moved to applications with more
  • Organizations developed less software in-house
    and bought relatively more from software vendors
  • System developers job went through a transition
    from builder to integrator

  • Fifth step 1990s
  • Developers used visual programming environments,
    such as power builder or visual basic, to design
    the user interfaces for systems that run on
    client/server platforms
  • Databases become relational or object oriented,
    and which may have been developed using software
    from firms such as Oracle, Microsoft. resided on
    the server
  • Application logic resided on the same server with
    the database, alternatively, an organization may
    have decided to purchase its entire enterprise
    wide system
  • More and more systems development efforts
    focused on the Internet, especially the web

  • Sixth step the new century
  • The focus on developing systems for the Internet
    and for firms intranets and extranets
  • Many CASE tools, such as those developed by
    Oracle, now directly support Web application
  • System implementation involves a three-tier
    design, with the database on one server, the
    application on a second server, and client logic
    located on user machines
  • Moving to wireless system components, wireless
    devices, such as cell phones
  • In some cases organizations not only do not
    develop the application in-house they dont even
    run the application in-house, choosing instead to
    use the application on a per-use basis by
    accessing in through an application service
    provider (ASP)

Characteristics of Systems
  • A system interrelated components working together
    for a common purpose
  • Information system (IS)
  • Arrangement of people, data, processes,
    information presentation and information
    technology that interact to support and improve
    day-to-day operations in a business as well as
    support the problem-solving and decision-making
    needs of management and users

Characteristics of Systems
  • Systems are made up of interrelated subsystems
    (e.g. a nuclear reactor is composed of boilers,
    reactor components etc.)
  • Functional decomposition dividing a system into
    components based on subsystems (which are in turn
    further divided into subsystems)
  • Functional Non-Functional components of a
  • System boundary the separation between a system
    and its environment (where inputs and outputs
  • Automation boundary separation between the
    automated part of system and the manual part

Characteristics of Systems
The system boundary and the automation boundary
Environment Surrounding the System
System boundary
Manual Part of the System
Automated Part of the System
Automation boundary
Characteristics of Systems
General Depiction of a System
Information System Components
  • Information systems have five key components
    hardware, software, data, processes, and people

Information System Components
  • Hardware
  • Is the physical layer of the information system
  • Hardware includes work stations, servers,
    networks, telecommunication equipments, cables,
    input and output devices and many others.
  • Hardware has become more powerful that give
    information systems more opportunities, and it
    also cut costs by becoming less expensive.

Information System Components
  • Software
  • Software refers to the programs which control the
    hardware and produce the desired information and
  • Software consists of system software and
    application software
  • System software manages the hardware components,
    which can include a single workstation or global
    network. Examples of system software include
  • operating systems
  • security software, that protects the computer
    from intrusion
  • utility programs, that handle specific tasks such
    as data backup and disk management.
  • Network operating system (NOS), which controls
    data, provide data security, manage network

Information System Components
  • Software
  • Application software, the programs that support
    day-to day business functions and provide process
    and manage the information user need. Application
    software can serve one or any number of users.
    Examples of company-wide applications, called
    Enterprise applications, include order processing
    system, payroll systems, and company
    communication network
  • Application software includes horizontal and
    vertical systems
  • A horizontal system is a system, such as an
    inventory or payroll application, that can be
    adapted for use in many different types of
  • A vertical systems is designed to meet the unique
    requirements of a specific business, such as a
    medical practice, or a video chain.

Information System Components
  • Data
  • Is the raw material that an information system
    transforms into useful information
  • Data can be stored in various locations, called
  • The system can extract specific information by
    linking the tables
  • Processes
  • Define the tasks and business functions that
    users, managers, and IT staff members perform to
    achieve specific results
  • Processes are the building blocks of an
    information system
  • Processes represent actual day-to-day business

Information System Components
  • People
  • those who operate the system those who provide
    its inputs and consume its outputs, and those who
    provide manual processing activities in a system,
    Users are the people who interact with an
    information system, both inside and outside the
  • We can divide users to two types internal and
  • Internal users include administrators, managers,
    technicians, sales staff, and corporate officers
  • External users include customers who track their
    orders on the companys Web site and suppliers
    who use a customers system to plan their
    manufacturing schedules.

Sequence Summary
  • In this sequence, you learned about how systems
    analysis and design in organizations has changed
    over the past 40 years
  • A system interrelated components working together
    for a common purpose
  • Information system (IS) is arrangement of people,
    data, processes, information presentation and
    information technology that interact to support
    and improve day-to-day operations in a business
  • Systems are made up of interrelated subsystems
    can be divided into sub systems depending on its
  • The essential components of an information system
    are hardware, software, data, processes, and

Sequence Summary
  • In this Sequence we have
  • Described how systems analysis and design in
    organizations has changed over the past 40 years
  • Defined the terms system and information system
  • Described the characteristics of system
  • Described information system components

  • 1 System Analysis and Design, Sixth Edition
  • Authors Gary B. Shelly, Thomas J. Cashman and
    Harry J. Rosenblatt ,
  • 2 Modern Systems Analysis and Design Third
  • Authors Jeffrey A. Hoffer , Joey F. George,
    Joseph S. Valacich
  • Publisher prentice hall
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