Unit 3 Study Guide
A comprehensive review of all Unit 3 content for exam preparation.
Unit Overview
Unit 3 focuses on developing computer-based systems and producing spreadsheet and database solutions. Students study systems analysis and development, then apply managing data skills using spreadsheets and databases.
Core Knowledge Areas
Systems Analysis
Systems Development Life Cycle
Study this topic →Project Management
Study this topic →Context Diagrams
Study this topic →Hardware & Software
Study this topic →CPU & Fetch-Execute Cycle
Study this topic →Troubleshooting & Maintenance
Study this topic →Ethics, Privacy & Etiquette
Study this topic →Managing Data
Key Skills Checklist
Systems Analysis and Development
- Describe each stage of the SDLC and explain why it is cyclical
- Create and analyse context diagrams using Yourdon/DeMarco notation
- Explain the components of project management (planning, scheduling, budgeting, tracking)
- Describe hardware components and the boot process
- Explain CPU components and the fetch-execute cycle
- Apply systematic troubleshooting steps
- Discuss ethical and privacy issues in ICT
Managing Data
- Build spreadsheet solutions using formulas, functions, and charts
- Use VLOOKUP and conditional functions (COUNTIF, IF)
- Explain the data hierarchy and select appropriate data types
- Distinguish between data integrity and data redundancy
- Design and build a single-table database
- Create forms, queries, and reports
- Document database solutions with a data dictionary
Quick Reference Definitions
- SDLC
- Systems Development Life Cycle - a structured approach with stages: preliminary analysis, analysis, design, development, implementation, evaluation and maintenance.
- Context Diagram
- A single-process view of a system showing external entities and data flows. Uses Yourdon/DeMarco notation.
- Data Integrity
- The accuracy and consistency of data throughout its lifecycle.
- Data Redundancy
- Unnecessary duplication of data, which can lead to inconsistencies and wasted storage.
- SOE
- Standard Operating Environment - a baseline system configuration used across an organisation.
- Primary Key
- A field that uniquely identifies each record in a table. Must be unique, not null, and unchanging.
Common Mistakes to Avoid
- ❌ Using multiple processes in a context diagram (should be ONE only)
- ❌ Confusing data integrity (correctness) with data redundancy (duplication)
- ❌ Mixing up formula (=B2*C2) with function (=SUM(B2:B10))
- ❌ Forgetting to label data flows in diagrams
- ❌ Skipping documentation steps in database tasks
Practice Prompts
Use these prompts to test your knowledge using glossary command terms:
- Describe the stages of the SDLC.
- Explain why a context diagram uses a single process.
- Analyse a troubleshooting scenario and recommend a solution.
- Construct a spreadsheet to model a budget with functions and charts.
- Create a single-table database with queries and reports.
- Compare data integrity and data redundancy.
- Justify your choice of primary key for a given scenario.