System Design Basics

System Design Basics

• Hardware: the physical parts of a computer
• Software: instructions for operating the computer and performing tasks, composed of programs and data
• Peripherals: external hardware devices
• Computer Network: interconnected systems sharing resources and data
• Human Resources: People in an organization who fulfill business objectives

Roles in a Networked World

• Client: hardware/software requesting a service
• Server: hosts and fulfills client requests
• Email Server: sends emails between clients
• Domain Name Server: translates domain names to IP addresses for device communication, uses the TCP/IP protocol suite
• Router: directs data packets to computer networks
• Firewall: a security measure to prevent unauthorized network access
• Dumb Client: a device with a keyboard, monitor, and network card, connected to a server
• Thin Client: the low-performance terminal relies on a server

Social and Ethical Issues

• Privacy: the misuse of personal data without consent can have security consequences
• Job displacement: automation and AI can replace human workers, resulting in job losses
• Reliability: how well an IT system functions; computer failure causes data loss, corruption, and other losses
• Integrity: the completeness and accuracy of data that is incomplete, out of date, or altered
• Digital Divide: the gap between those with and without access to digital machines
• Bias/Discrimination: higher error rate for those with darker skin tones
• Cybersecurity: the increased risk of cyberattacks and data breaches
• Honorable mentions: inconsistency, surveillance, globalizations, IT policies, standards and protocols, people and machines, digital citizenship

The positive effects of devices can include

• More Informed about the world
• Email for communication
• Easier communication and emergency communication
• Better hand-eye coordination (gaming)

The negative effects of devices can include

• Psychological impacts
• Obstacle 1-to-1 relationships and neglecting real life
• Social media obsessions
• Anxiety
• Expensive hardware
• Lower levels of concentration, health consequences, car accidents, and neglecting education

Stakeholders

• Stakeholders are not a single person
• Stakeholders are individuals, teams, groups or organizations with interest in a project or its outcome
• End users are the people who will use the product
• Frequent users of the current system can also be stakeholders
• Stakeholders can identify flaws and propose update suggestions
• Managers and supervisors can provide comments and advice

Obtaining Requirements from Stakeholders

• Information gathering about the existing system and obtaining stakeholder requirements will involve
• Stakeholder Interviews: these gather stakeholder information through face-to-face exchanges
• Structured Interviews: these are strictly standardized and prescribed
• Unstructured Interviews: these are flexible and encourage stakeholders to freely express thoughts and personal beliefs

Advantages of Interviews

• In-depth data collection
• Flexibility
• Understanding context
• Personal interaction

Disadvantages of Interviews

• Time-consuming and costly
• Potential for bias
• Limited generalizability
• Difficulty reaching participants
• Variability in data quality
• Lack of anonymity

Questionnaires

• Questionnaires gather information from large groups of stakeholders
• Questionnaires are useful for gathering specific information online or in person
• Closed Questionnaires: these involve yes/no, boxes, and short responses for tabular data and statistical analysis
• Open Questionnaires: free-response questions that provide a deeper response but are more difficult to interpret

Advantages and Disadvantages of Questionnaires

• Guarantees uniformity
• Easier to analyze compared to interview information
• Questions should not be black and white or difficult to expand on
• Open questionnaires are more personal and allow for deeper dives to be more intuitive

Direct Observation of Current Procedures

• Time-and-motion study shows where procedures and processes could be more efficient and identify bottlenecks
• It Helps identify areas the project team can improve
• Involves spending time in different departments, observes stakeholders, and gains valuable insights
• Pros: Collects different types of info, familiarizes the analyst with the case study and processes
• Cons: Time-consuming, people change their behavior, may feel watched, Hawthorne effect may apply

Reading Documentation

• It is easy to understand the technical details of the current system
• Helps project teams to identify lacking areas and where improvements can be made
• Includes architecture, components, and integration points

Techiniques for Gathering Information Needed

• Examining the current system, competing products, and organizational capabilities are important for planning
• Examining help to identify areas for improvement and provide insights
• Literature search: identifies, retrieves, and manages sources in order to derive conclusions and develop guidelines
• Examining Current Systems: a process involving detailed examination, function-procedure analysis, and studying business/system documents
• Competing Products: analyzes competitive factors, benefits, vulnerabilities, and user acceptance
• Provides information about the market and similar items
• Organizational Capabilities: the successful IT systems should have a competitive advantage. They require sense-making, decision-making, asset availability, and operations management.
• Modern information systems should increase client trust, preserve brand strength, maintain corporate resiliency, and enhance organizational piece

Overall System Integration

• Integrate a new system effectively with existing systems and processes
• Support IT system planning and developing
• Identify limitations and constraints that may impact the deployment/adoption
• Informs design development

Representing System Requirements

• System requirements is specified in a requirements specification document
• This defines customer requirements
• Types of processing: includes a system analysis, and can be used to test the dydtem after implementation to evaluate

Types of Processing

• Online Processing: data processing via equipment control, such as airline reservations
• Real-Time Processing: immediate data processing where generated data influences the ongoing process, like aircraft control
• Batch Processing: data processing composed and processed as a single unit, such as payroll

System Flow Charts

• System flow charts describes the processing system, which excludes program details
• System flow charts Shows the flow of processes and decisions
• System flow charts represent how the system should run
• System flow charts are able to show batch, real-time and online processing
• Data Flow Diagrams: shows how data moves through a system and data stores
• Data Flow Diagrams focuses on movement and transformation
• Structure charts: describes a system's functions and sub-functions describing how modules interact, which makes design much easier

Modular Design

• Modular Design: designs system modules individually and combines them as a solution
• Module: A self-contained code piece performing a specific function
• Modular Programming/Modularity: partitions a computer program into sub-programs so that each subprogram may be easily modified
• Modular Language: language that supports modular programming

Prototype

• Prototype: Preliminary version of the final product
• A simple version of the final system that is used as a design phase
• Demonstrates how the product will work
• Prototypes attract client attention and encourage feedback
• Provides vision for investor
• Encourages user and developer participation
• Helps identify inefficiencies and increases system development speed

Iteration in Design Process

• Iteration: repeating instructions until the operations deliver a desired system
• Impossible to design a perfect system without initial usability issues
• Designers must reconsider their choices
• Therefore, an iterative design methodology is adopted
• Software development benefits from steady design improvements involving evaluation and testing
• User testing also ensures that the produced design may have to be run through by the producer again and again

User Involvment Importance

• Analysis and design must involve stakeholders for a successful system
• User involvement, collaboration, and participation are needed because stakeholder goals are unlikely to be successful
• A Developed System has to solves real problems and deal with issues to deal with issues of project scope

Social and Ethical Concerns

• Machines replace humans for unemploymenent
• Jobs don't vanish, they just change
• Robotics and Al can replace many workers, creating social effects
• New technologies and apps have impacts, continuous devlopment
• Social Impacts and beliefs which involves improving human life
• Computerized systems can absorb people and drift them from the physical world, enclosing them in virtual ones
• Smart homes deprive people of socialization
• New systems increase employee stress as they study and familiarize themselves

Usability and Accessibility

• Accessibility: service, product, or environment potential to serve and meet individual needs
• High accessibility: meets the needs of many people
• Low accessibility: barriers to specific groups
• Accomodating those with disabilities & the use of assistive technologies
• Usability: application or website potential to accomplish user goals
• Ergonomics: it refers to human engineering designed to be safe and comfortable products designed around human consideration

Usability

• Components: includes complexity and simplicity, effectiveness, efficiency, error, learnability, memorability, readability, and satisfaction
• Usability Problems: include GPS/navigation issues, tablets, consoles, PCs, and digital cameras
• Methods: include Braille input devices, speech output, and screen readers Visual Impairment: mostly use touch with standard keyboards Colour Blindness: adjust bg and foreground Hearing/Speech Impairments: replace with visual effects, use subtitles

Methods for Impairments

• cognitive problems/learning disabilityes: special software that provides active participation
• mobility impairments, limited hand mobility, parkinson disease: use special disk guides

Range of Usability Problems

• If an interface is unappealing, users won't be attracted
• Successful intranets increase employee productivity and decrease wasted time

The Usability Quality Component and Usability Considerations for ticketing systems Include:

• Complexity/Simplicity: unclear instructions, limited help
• Effectiveness: not following standards, confusing to foreign users
• Efficiency: a complicated site makes unnecessary actions
• Error: user mistakes for tickets, has to restart booking
• Satisfaction: it causes customer dissatisfaction

Moral, Ethical, Social, Economic, and Environmental Implications

• AI and robotics challenge traditional perspectives. It poses a hard queston: how to replicate on computer
• Predictions for the near future is that computers will have a kind of intelligence
• IT has increased paper usage (landfills)
• Recycling requires chemicals and energy + environmental impact
• E-waste: contains hazardous materials
• Digital Divide: is not equally in most countries
• Elements such as laptops, smartphones, multimedia, and file shring have an impact due to the "digital divide."