GCE A/L ICT Unit 7 - System Analysis & Design Exam Questions and Answers

📘 GCE A/L ICT Unit 7

System Analysis & Design

Comprehensive exam-focused notes for Sri Lankan GCE Advanced Level ICT

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📌 Introduction & Information Systems

Unit 7: System Analysis & Design is one of the most important units in GCE A/L ICT (Sri Lanka Local Syllabus). It is heavily tested in MCQ, structured, and essay questions.

🔹 What is an Information System?

An Information System is a collection of people, hardware, software, procedures, and data that work together to process data into meaningful information.

Key Idea:
Input → Processing → Output (Information)

🔹 Components of an Information System

Component	Description	Example
People	Users, operators, developers	Teachers, students, IT staff
Hardware	Physical devices	Computers, servers, printers
Software	Programs and applications	Operating systems, DBMS, apps
Procedures	Rules and instructions	User manuals, backup policies
Data	Raw facts and figures	Student records, marks, attendance

🔄 SDLC – System Development Life Cycle

SDLC Definition: A structured process used to develop information systems efficiently through defined phases.

🔹 The 8 Phases of SDLC (In Order)

1. Planning
   • Identify problem/need
   • Define project scope
   • Allocate resources
2. Feasibility Study
   • Evaluate if project is practical
   • Check TELOS factors
   • Decide: Proceed or stop?
3. System Analysis
   • Study current system
   • Gather user requirements
   • Create Requirement Specification Document
4. System Design
   • Design database (ERD)
   • Create DFDs
   • Design UI/UX mockups
5. Development
   • Write actual code
   • Build database
   • Integrate modules
6. Testing
   • Find and fix bugs
   • Unit, integration, system testing
   • User acceptance testing (UAT)
7. Implementation
   • Deploy system for real use
   • Train users
   • Migrate data from old system
8. Maintenance
   • Fix post-launch issues
   • Apply updates and patches
   • Add new features as needed

🎯 Exam Tip: Memorize the 8 phases IN ORDER. A common 4-5 mark question asks you to list and briefly explain them. Use mnemonic: "Please Find Smart Developers Testing In Modern Labs"

📊 Feasibility Study (TELOS)

🔹 Purpose of Feasibility Study

❓ Key Question: "Is this system worth developing?"
Evaluates if the project is practical, affordable, and achievable before committing resources.

🔹 TELOS Feasibility Factors

Factor	Key Question	Example
Technical 🔧	Do we have the technology & skills?	Need mobile app developers, cloud server access
Economic 💰	Do benefits exceed costs?	Cost: Rs.500k | Benefit: Rs.1.2M over 4 years → ✅ Feasible
Legal ⚖️	Does it comply with laws?	Data protection laws, software licensing requirements
Operational 👥	Will users accept and use it?	Can teachers learn the new system without extensive training?
Schedule 📅	Can it be completed on time?	Can we finish before the next academic year begins?

🔹 Economic Feasibility Formula

Project is feasible if:
Expected Total Benefits > Development Cost + Operational Costs

Example Calculation:

• 💸 Development Cost: Rs. 500,000
• 📈 Annual Benefit: Rs. 300,000 × 4 years = Rs. 1,200,000
• ✅ Net Gain: Rs. 700,000 → Project is economically feasible!

🎯 Exam Trick: If asked "Explain feasibility study", use the TELOS structure + one calculation example for full marks. Always link each factor to a real-world scenario.

🔍 Fact-Finding Techniques

🔹 Purpose

Techniques used during System Analysis to gather accurate information about user requirements and current system problems.

🔹 Four Main Techniques

Technique	Advantages	Disadvantages	Best Used When
Interviews	• Detailed information • Clarification possible • Builds rapport	• Time-consuming • Expensive • Interviewer bias possible	Small group of key users; complex requirements
Questionnaires	• Fast data collection • Reaches many users • Cheap to distribute	• Low response quality • Misunderstandings possible • No immediate clarification	Large user base; simple, structured questions
Observation	• Real environment analysis • Accurate process understanding • Unbiased data	• Time-consuming • Users may behave differently • Cannot observe thoughts	Understanding actual workflow; verifying reported processes
Document Study	• Reliable historical data • No user interruption • Verifies other findings	• May be outdated • Incomplete records • Time to analyze	Understanding existing procedures; validating user claims

💡 Exam Trick: If question says "compare" or "discuss", ALWAYS give advantages + disadvantages for each method. Use a table format if allowed for clarity and full marks.

🔷 Data Flow Diagrams (DFD)

🔹 What is a DFD?

A Data Flow Diagram (DFD) is a graphical representation showing how data moves through a system – from input, through processes, to output and storage.

🔹 DFD Symbols (MEMORIZE FOR EXAMS)

Symbol	Name	Meaning	Example
○ Circle	Process	Transforms input to output	"Calculate Marks", "Validate Login"
➜ Arrow	Data Flow	Movement of data	"Student Details", "Payment Info"
▭ Rectangle	External Entity	Source/destination outside system	Student, Admin, Bank, Supplier
▭▭ Open Rectangle	Data Store	Where data is stored	Student File, Database, Transaction Log

🔹 Levels of DFD

• Context Diagram (Level 0): Entire system as ONE process + external entities only. NO data stores or internal processes.
• Level 1 DFD: Breaks system into major sub-processes with data stores and flows.
• Level 2+ DFD: Further decomposition of individual processes from Level 1.

🔹 Context Diagram – EXAM CRITICAL

✅ What it Shows:

• The whole system as a single process (one circle)
• All external entities interacting with it (rectangles)
• Data flows between entities and system (labeled arrows)

🔹 How to Draw: 4 Simple Steps

1. Identify the System
   Example: [ Library Management System ]
2. Identify External Entities
   Example: [Student] [Librarian] [Supplier]
3. Map Inputs & Outputs

   Entity	Input to System	Output from System
   Student	Book request, Return book	Confirmation, Due date, Fine notice
   Librarian	Add book, Update record	Report, Inventory list

4. Draw Labeled Arrows
   [Student] → Borrow Request → [System] → Confirmation → [Student]

🔹 Critical Rules (MCQ Gold)

✔ MUST DO:

• Only ONE process circle (the whole system)
• NO internal processes or data stores
• ALL external entities must be shown
• EVERY arrow must have a clear descriptive label
• Arrows show direction of data flow

❌ AVOID THESE MISTAKES:

• Drawing multiple process circles ❌
• Adding database/data store symbols ❌
• Unlabeled or ambiguously labeled arrows ❌
• Missing key entities mentioned in question ❌
• Arrows with no direction or bidirectional without justification ❌

🎯 Exam Focus: Context Diagram questions appear almost every year (6-10 marks). Practice drawing for: Library System, School Admission, Hospital Appointment, Bank ATM.

📄 DFD Past Paper Questions + Answers

🔹 Question 1: Context Diagram

Q: Draw a Context Diagram for a Library Management System. (6 marks)

✅ Model Answer Structure:

1. Center: [ Library Management System ] (single process circle)
2. External Entities (rectangles around system):
   • Student
   • Librarian
   • Supplier (optional but good to include)
3. Data Flows (labeled arrows):
   • Student → System: Borrow request, Return book, Fine payment
   • System → Student: Book details, Due date, Fine notice, Confirmation
   • Librarian → System: Add book, Update record, Generate report
   • System → Librarian: Overdue list, Inventory report, Member status
   • Supplier → System: New books list, Price update
   • System → Supplier: Order request, Payment confirmation

✨ Marking criteria: 1 mark for correct single process, 1 mark per entity (max 3), 1 mark per correctly labeled flow (max 3)

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🔹 Question 2: Level 0 DFD

Q: Draw Level 0 DFD for a School Admission System. (8 marks)

✅ Model Answer Structure:

Processes (numbered circles):

• 1.0 Receive Application
• 2.0 Verify Documents
• 3.0 Process Application
• 4.0 Generate Admission Result

Data Stores (open rectangles):

• D1: Application File
• D2: Student Database
• D3: Result Log

Key Data Flows:

• Parent → 1.0: Completed application form
• 1.0 → D1: Store application details
• 2.0 → D2: Check student eligibility
• 3.0 → 4.0: Approved application data
• 4.0 → Parent: Admission letter / Rejection notice

✨ Marking criteria: Correct symbols (2), Proper numbering 1.0, 2.0... (2), Balanced flows (2), Labeled arrows (2)

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🔹 Question 3: DFD Symbols

Q: Identify and explain the four symbols used in DFD. (4 marks)

✅ Model Answer:

Symbol	Name	Purpose
○ Circle	Process	Represents an action that transforms input data into output data
➜ Arrow	Data Flow	Shows the movement of data between processes, entities, and stores
▭ Rectangle	External Entity	Represents a person, organization, or system outside the boundary that interacts with the system
▭▭ Open Rectangle	Data Store	Represents a location where data is stored for later use (file, database, etc.)

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🔹 Question 4: Context vs Level 0 DFD

Q: Differentiate between a Context Diagram and a Level 0 DFD. (4 marks)

✅ Model Answer:

Context Diagram	Level 0 DFD
Shows the whole system as ONE single process	Breaks the system into multiple main sub-processes
NO internal processes shown	Internal processes ARE shown and numbered (1.0, 2.0...)
NO data stores included	Data stores ARE included (open rectangles)
Highest level, shows system boundaries only	First level of decomposition, shows major data flows internally

🧪 System Testing & Conversion

🔹 Types of System Testing

Testing Type	Purpose	Performed By	When
Unit Testing	Test individual modules/functions in isolation	Programmers/Developers	During development phase
Integration Testing	Test combined modules working together	Developers + Testers	After unit testing, before system test
System Testing	Test complete integrated system against requirements	Independent testing team	After integration, before user acceptance
Acceptance Testing (UAT)	Verify system meets user needs and is ready for launch	End users / Client	Final stage before implementation

🔹 System Conversion Methods

Method	How It Works	Advantages	Disadvantages	Best For
Direct Changeover	Old system stopped; new system starts immediately on a set date	• Fast • Low cost • No dual maintenance	• High risk • No fallback option • Users unprepared	Small, low-risk systems with simple data
Parallel Running	Old and new systems run simultaneously for a period	• Safer • Easy comparison • Fallback available	• Expensive • Double workload • Staff confusion possible	Critical systems (banks, hospitals, exam systems)
Pilot Running	Implemented in one department/branch first, then rolled out	• Reduced risk • Real-world testing • Lessons for full rollout	• Slower full implementation • Pilot group may feel burdened	Large organizations with multiple branches
Phased Implementation	Modules/functions replaced gradually over time	• Easier management • Users adapt gradually • Problems isolated	• Takes longer • Temporary interfaces needed • Complex coordination	Complex modular systems (ERP, school management)

🎯 Exam Answer Template:
"For a hospital patient record system, I would recommend Parallel Running because:
✓ Critical patient data must not be lost or corrupted
✓ Old system can run as backup during transition
✓ Medical staff can be trained gradually while still using familiar system
✓ Any errors in new system can be fixed without stopping patient care"

🔧 System Maintenance & Exam Focus

🔹 Types of System Maintenance

Type	Purpose	Example
Corrective Maintenance	Fixing errors, bugs, or faults discovered after launch	Fixing a calculation error in the grading module
Adaptive Maintenance	Adapting system to changes in environment or requirements	Updating system to comply with new data protection law
Perfective Maintenance	Improving performance, usability, or adding new features	Adding mobile app access to existing web-based system
Preventive Maintenance	Preventing future problems through proactive measures	Regular database optimization to prevent slowdowns

🔹 Exam Focus Areas (High Frequency Topics)

⭐ Topics That Appear Almost Every Year:

• SDLC phases – List, explain, or put in order (4-8 marks)
• Feasibility Study (TELOS) – Explain factors with examples (5-10 marks)
• DFD Drawing – Context Diagram or Level 0 DFD (6-15 marks)
• Fact-Finding Techniques – Compare advantages/disadvantages (5-10 marks)
• Testing Types – Define and differentiate (4-8 marks)
• Conversion Methods – Explain with suitable examples (5-10 marks)
• Maintenance Types – Define with examples (3-6 marks)

🔹 Quick Revision Checklist

Topic	Key Point to Remember
SDLC Order	Planning → Feasibility → Analysis → Design → Development → Testing → Implementation → Maintenance
TELOS	Technical, Economic, Legal, Operational, Schedule – one question per factor
Context Diagram	ONE process, NO data stores, ALL entities shown, EVERY arrow labeled
DFD Symbols	Circle=Process, Arrow=Flow, Rectangle=Entity, Open Rect=Store
Testing Sequence	Unit → Integration → System → Acceptance (in that order)
Conversion Risk	Direct = Highest risk, Parallel = Safest but costliest
Maintenance	Corrective=Fix bugs, Adaptive=Change for environment, Perfective=Improve

🧠 FINAL EXAM DAY REMINDERS

👉 For DFD Questions:
✓ Draw neatly with pencil & ruler
✓ Label EVERY arrow with descriptive data name
✓ Use correct symbols ONLY (no databases in Context Diagram!)
✓ Show ALL external entities mentioned in question
✓ Keep Context Diagram as ONE process box only

👉 For Essay Questions:
✓ Start with clear definition
✓ Use structured paragraphs with topic sentences
✓ Include relevant local examples (school, bank, hospital)
✓ End with brief conclusion linking to real-world value

✨ You've prepared well. Trust your knowledge. All the best! ✨