IT systems

• IT system

  Comprehensive framework that incorporates different components to manage, process, store, and disseminate information for various purposes within an organization or for personal use
• Components of an IT system


  • Hardware
  • Software
  • Processes
  • People
• Hardware

  Physical components of the IT system, including computers, servers, storage devices, networking equipment, and other peripherals like printers and scanners
• Software


  • Operating systems
  • Applications
• Processes


  Series of steps or activities that are designed to achieve a specific outcome, including workflows, protocols, and procedures that govern how data is collected, processed, stored, and transmitted
• People in an IT system


  • End users
  • IT professionals
  • Developers
  • Stakeholders
• System decomposition


  Breaking down a complex system into smaller, manageable parts that are easier to understand, design, implement, and maintain
• Steps for system decomposition


  1. Identify high-level components

  2. Analyze functionalities

  3. Identify sub-systems

  4. Define interfaces

  5. Consider separation of concerns

  6. Identify dependencies

  7. Encapsulate complexity

  8. Consider reusability

  9. Balance cohesion and coupling

  10. Iterate and refine

  11. Document the decomposition
• Fitness for purpose


  The extent to which a particular system meets the specific needs, requirements, and objectives for which it was designed or intended
• Aspects of fitness for purpose


  • Alignment with requirements
  • Effectiveness
  • Efficiency
  • User satisfaction
  • Reliability and stability
  • Adaptability and scalability
  • Compliance and standards
  • Cost-effectiveness
  • Maintainability and supportability
• Data Flow Diagram (DFD)


  Graphical tool used by analysts and designers to represent the flow of data within a system and between external entities and the system itself

  
• Why Data Flow Diagrams


  • Understanding system requirements
  • Communication and collaboration
  • Identifying system boundaries
  • Identifying data sources and destinations
  • Analyzing system processes
  • Detecting anomalies and redundancies
  • System maintenance and upgrades
• Data sources


  Origins of data that enter the system, such as external entities like users or sensors
• Data Flow Diagrams (DFDs)


  • Reveal anomalies and redundancies in data flow
  • Serve as a reference point for system maintenance and upgrades
• Data Flow Diagrams help in understanding, visualizing, and communicating the flow of data within a system, leading to the development of efficient and effective systems that meet user requirements
• Data sources


  Origins of data that enter the system, can be external entities or internal to the system
• Processes


  Functions or activities performed on data, take inputs, process them, and produce outputs
• Data Stores

  Repositories of data, can be databases, files, or any other storage system
• Data Flows


  Arrows representing the movement of data between processes, data stores, and external entities
• Flowcharts


  • Provide a clear, visual representation of processes
  • Allow for process analysis and improvement
  • Facilitate communication
  • Serve as training and documentation tools
  • Aid in problem-solving
  • Contribute to standardization
  • Support project planning
• Input/Output


  Parallelograms representing data or materials entering or exiting the process
• Processes


  Rectangles representing actions or operations in the workflow
• Subprocess


  A defined process, could be another flowchart
• Decision Points


  Diamond-shaped symbols representing points in the process where a decision is made
• Start and End Points

  Oval or rounded corner rectangle symbols representing the initiation and completion of the process
• Connectors


  Arrows or lines connecting symbols, indicating the flow of the process
• Loops and Repetition


  Curved or circular arrows indicating that a certain set of steps needs to be repeated until a condition is met
• Advantages of IT Systems for Individuals


  • Access to information
  • Communication
  • Convenience
  • Entertainment
  • Collaboration
  • Skill development
• Disadvantages of IT Systems for Individuals


  • Privacy concerns
  • Addiction
  • Isolation
  • Security risks
  • Dependency
• Advantages of IT Systems for Organizations

  • Efficiency
  • Data management
  • Communication and collaboration
  • Customer service
  • Cost reduction
  • Innovation
• Disadvantages of IT Systems for Organizations

  • Security threats
  • Dependency and downtime
  • Training and skill gaps
  • Integration challenges
  • Legal and compliance risks
• Digital devices used in IT systems


  • Computers
  • Smartphones and Tablets
  • Wearable Devices
  • Printers and Scanners
  • Keyboards and Mice
  • Webcams and Microphones
  • External Drives and Memory Cards
  • Hard Disk Drives (HDDs) and Solid-State Drives (SSDs)
  • Network Attached Storage (NAS) Devices
  • RAM (Random Access Memory)
  • ROM (Read-Only Memory)
  • Flash Memory