Notes: Topic 1 Computer Science

System Fundamentals

Topic Overview

  • Introduction to the fundamentals of systems.

Identifying System Context

Key Aspects to Consider

  • Problem Definition: Identify what problem the new system aims to solve.

  • Alternative Solutions: Explore possible existing solutions.

  • Staffing Considerations: Assess required number of staff and training needs.

  • Cost Assessment: Examine the overall budget for system implementation.

  • Time Constraints: Establish a timeline for deployment.

  • Compatibility: Ensure compatibility with existing systems.

  • Infrastructure Needs: Understand network requirements.

  • Software Options: Compare bespoke versus off-the-shelf software.

Software Types: Bespoke vs Off-the-shelf

Bespoke Software

  • Tailored to specific needs.

  • Pros: Customizable features.

  • Cons: High cost and potential training needs.

Off-the-shelf Software

  • Generalized solution for a wider audience.

  • Pros: Lower cost and availability of skilled workers.

  • Cons: May not fulfill all specific needs.

Change Management

Importance of Change Management

  • Communication: Effectively communicate the need for change and its benefits.

  • Training Needs: Identify user training requirements.

  • Recruitment: Hire staff with necessary skill sets if needed.

  • Stakeholder Support: Ensure involvement and support of stakeholders.

  • Project Planning: Set clear milestones and completion timelines.

  • System Compatibility: Address compatibility between old and new systems.

  • Testing: Implement thorough testing protocols.

Compatibility Issues

Factors Affecting Compatibility

  • Legacy Systems: Problems faced with outdated technologies when integrating.

  • Business Mergers: Issues arising from merging systems, such as:

    • Operating System discrepancies.

    • Incompatible data formats.

    • Hardware incompatibility.

  • Retention of Legacy Systems: Reasons for not replacing:

    • Functionality.

    • Costliness of new developments.

    • Resistance to retraining staff.

    • Lack of understanding of old systems.

System Implementation Options

Comparison of In-house vs Outsourced Hosting

  • In-house Management: More control but higher initial costs and recruitment of technical staff needed.

  • Outsourced Hosting: Lower initial costs, no technical staff needed, managed remotely.

  • SaaS (Software as a Service): Software and data managed externally, advantages and disadvantages include:

    • Cost efficiency in set-up and staffing.

    • Security and control risks with remote data management.

Installation Processes

Types of Installation Processes

  • Parallel Running: Operating both systems simultaneously, low risk but requires more resources.

  • Pilot Running: Testing the system in a limited capacity to minimize risk.

Data Migration Challenges

Issues Encountered During Migration

  • Incompatibility: Data formats and structures not aligning.

  • Incomplete Transfers: Data not fully migrated.

  • Standardization Issues: Adhering to international conventions.

  • Conversion Needs: Data often requires formatting changes prior to migration.

Testing Types

Overview of Testing Phases

  • Debugging: Continuous throughout development.

  • Alpha Testing: Early testing by developers.

  • Beta Testing: User testing for final adjustments.

  • White-box Testing: Tester knows code, focuses on implementation.

  • Black-box Testing: User-focused testing, no knowledge of internal workings.

  • Unit Testing: Individual components examined.

  • System Testing: Overall system is evaluated for coherence and functionality.

  • Acceptance Testing: Final user validation before launch.

  • Automated Testing: Utilization of software to test software.

Importance of Testing

  • Essential to avoid bugs that may affect productivity and satisfaction.

User Documentation Importance

Characteristics of Effective Documentation

  • Non-technical guidance aimed at end users.

  • Contains installation, operation, and troubleshooting advice.

  • Illustrated examples to ease user transition to new systems.

Methods of Providing User Documentation

Documentation Types

  • Paper Manuals: Accessible without a computer but require multiple copies.

  • Online Manuals: Rich media usage, searchable, and always accessible.

  • Interactive Tutorials: Engaging learning methods include direct user feedback.

  • Dedicated Support Teams: Personalized assistance but may increase costs.

Data Loss Causes and Consequences

Identifying Data Loss Causes

  • Viruses and Malware: Potential data corruption.

  • Natural Disasters: Events such as fires or flooding.

  • User Error: Accidental data deletions can lead to loss.

  • Hardware Failures: Physical device issues causing data loss.

Consequences of Data Loss

  • Operational disruptions, loss of customer orders, damaged reputation, and costs for data recovery.

Strategies for Preventing Data Loss

Methods to Protect Data

  • Back-ups: Regular back-ups crucial for data security.

  • Removable Media: Simple storage solutions but increased risk of loss.

  • Offsite Storage: Essential for disaster recovery.

  • Online Solutions: Need for constant internet access and security measures.

  • Antivirus Solutions: Protection from malware threats.

  • Redundancy and Failover: Ensuring backup systems are in place.

Managing Releases and Updates

Key Considerations

  • Continuous monitoring for bug fixes and updates.

  • Mechanisms for software to ensure users have the most recent versions without risking data integrity.

Definitions: Key Terms in System Context

  • Hardware: Physical components of a computing system.

  • Software: Electronic data and instructions.

  • Peripheral: External devices connected to a computer.

  • Network: Linked computers for communication.

  • Human Resources: Personnel involved in the operations.

Computer Roles in Networks

Key Functions

  • Client: Requests services from servers.

  • Server: Responds to client requests, handling data operations.

  • Email and DNS Servers: Manage email transactions and address translations, respectively.

  • Router: Directs network traffic appropriately.

  • Firewall: Controls data flow based on defined rules.

Firewall Functionality

Understanding Firewalls

  • Software or hardware that restrict data flow.

  • Manages information by closing specific ports, ensuring network security.

Social and Ethical Issues in Networking

Overview

  • Ethical concerns involving privacy, data accuracy, and health safety.

Stakeholders in New System Planning

Considering Stakeholders

  • Identify all potential stakeholders including end-users, employees, customers, and community members.

Methods for Gathering Stakeholder Requirements

Techniques

  • Surveys: Quickly gather information but may lack depth.

  • Interviews: Provide detailed insights but can be time-consuming.

  • Direct Observations: Relevant information without bias, yet may influence behavior.

Information Gathering Techniques for Solutions

Methods to Inform Development

  • Analyze current systems and identify user roles and needs.

  • Review competing products for innovative ideas.

  • Explore internal expert insights and literature reviews.

System Representations

Diagram Techniques

  • Structure Diagrams: Visual representations of system breakdowns.

  • Data Flow Diagrams (DFDs): Illustrate data movement in processes, important for software development.

Systems Flowchart Construction

  • Recognize the importance of exams and practice proper representation.

Prototyping and User Involvement

Benefits of Prototyping

  • Allows for immediate feedback and reduces long-term costs.

  • Essential for validating user requirements through active involvement.

Importance of Iteration in Design

Continuous Improvement

  • Facilitate changes based on user feedback and updates.

Consequences of Excluding End-users

Issues Arising from Exclusion

  • Risk of inappropriate system design leading to non-usage and wasted resources.

Summary of Social and Ethical Issues in Information Systems

Key Concerns

  • Privacy, data accuracy, compliance with laws, and the impact of automation on jobs.

Defining Usability

Key Usability Concepts

  • Learnability: Ease of initial task completion.

  • Efficiency: Speed of task accomplishment post-training.

  • Memorability: Ability to return to a system after an absence.

  • Errors: Frequency and recoverability from mistakes.

  • Satisfaction: User contentment with system use.

Improving Accessibility in Systems

Techniques for Enhancement

  • Various technologies like touch screens and voice recognition improve user interaction.

Usability Problems with Systems

Common Issues

  • Challenges faced with device navigation and function complexity.

Exploring Interaction Implications

Societal and Environmental Concerns

  • Issues include e-waste, reliance on technology, and its effects on employment.