Unit 11.1C · Term 1

Data Collection & Analysis

Before designing a new system, an analyst must understand the current system, collect evidence from stakeholders, analyse inputs, processes, outputs and data stores, identify requirements and compare possible solutions.

Learning Objectives

11.2.1.3 Describe data collection methods
11.2.1.4 Apply data analysis techniques
11.2.1.5 Compare alternative solutions

Success Criteria

I can select and justify an appropriate data collection method · distinguish open and closed questions · create a data collection plan · identify inputs, processes, outputs, data stores and constraints · convert findings into requirements · compare alternative solutions using technical, economic, operational and time feasibility.

Lesson Presentation

11.1C-data-analysis.pdf · Slides for classroom use

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Conceptual Anchor

The Doctor Analogy

A doctor does not prescribe treatment before examining the patient. A systems analyst works in the same way: collect evidence, understand the current problems, identify what needs to improve and then compare possible solutions.

From Problem to Proposed Solution

1. InvestigateUnderstand the current system and its users.

2. Collect DataInterview, questionnaire, observe and inspect documents.

3. AnalyseIdentify inputs, processes, outputs, stores and constraints.

4. RequirementsTurn evidence into clear system requirements.

5. CompareEvaluate alternative solutions using feasibility criteria.

Running Case Study — School Library System

The Current Situation

A school library uses a mixture of paper records and spreadsheets. The school wants to investigate whether a new digital system is needed. You are the systems analyst.

Problem 1: finding current loan information can take too long.

Problem 2: overdue books are not always identified quickly.

Problem 3: students cannot easily check whether a book is available.

Constraint: the school has a limited budget and existing computers should be reused where possible.

Studentssearch · borrow · return

Library Systembooks · members · loans

Librarianissue · return · reports

Cambridge-Style Video Reinforcement

Craig'n'Dave — Cambridge IGCSE: Software Development Life Cycle

Use this as a short overview. Pay particular attention to the Analysis stage at about 00:30.

While Watching

Write one sentence answering: Why must analysis happen before design and coding?

Data Collection Methods

No single collection method is always best. Analysts choose methods according to the stakeholder, the information required, available time and the need for detail or breadth.

Interview

Direct conversation. Allows follow-up questions and detailed clarification.

depth

Questionnaire

Standard questions for many users. Efficient for broad responses and countable results.

large audience

Observation

Watch real tasks to understand actual workflow, timings and workarounds.

real workflow

Document Review

Examine existing forms, records, manuals and reports.

existing evidence

Focus Group

Structured discussion with selected users to explore several perspectives.

multiple views

Method	Strength	Limitation
Interview	Detailed answers; questions can be clarified and followed up.	Time-consuming; not suitable for very large numbers.
Questionnaire	Standardised responses from many people efficiently.	Low response rate or limited depth.
Observation	Shows how the system is actually used in real time.	Time-consuming; users may behave differently when watched.
Document Review	Provides existing forms, records and documented evidence.	Documents may be outdated or incomplete.
Focus Group	Generates several viewpoints and discussion.	Dominant participants may influence others.

Which Method Should the Analyst Use?

Choose the most suitable primary method and justify your choice.

Open vs Closed Questions

Question Design

Open questions invite explanations, opinions or descriptions.

What problems do you experience when issuing or returning books?

Closed questions restrict the answer to predefined choices and are easier to count.

Do you use the library at least once per week? YES / NO

Open or Closed?

Classify the question before checking the explanation.

Data Collection Plan

A strong analysis combines evidence from several sources. Decide who to investigate, which method to use and what information is needed.

Stakeholder / Source	Method	Information Needed	Why?
Librarian	Interview	Daily workflow, problems, reports	Detailed follow-up is possible.
Students	Questionnaire	Frequency of use, search needs, difficulties	Reaches many users efficiently.
Issue / return desk	Observation	Actual steps, timing, repeated work	Shows real practice.
Forms / spreadsheets	Document Review	Current fields, codes, reports and records	Reveals existing stored data.

Analyse the Current System

After collecting evidence, organise it into inputs, processes, outputs, data stores and constraints.

Inputs

Student ID
Book ID
Borrow / return request
New book details

Processes

Check availability
Issue book
Record return
Calculate overdue status

Outputs

Loan confirmation
Availability result
Overdue list
Inventory report

Data Stores

Books
Students
Loans
Returns

Constraints

Limited budget
Existing PCs
Term deadline
Staff training time

Exam Technique

When asked to analyse, apply the technique to the scenario. Write “Book ID is an input used to identify the book being borrowed” rather than only “Input: Book ID.”

Simple Data Flow View

A DFD shows how data moves between external entities, processes and data stores. This simplified example focuses on borrowing a book.

StudentStudent ID + Book ID

Borrow request →

Process Loancheck availability + create loan

read / update →

Loans & Books Dataavailability + active loan records

DFD Reminder

A DFD describes data flow, not the detailed sequence of program instructions. Do not confuse it with a program flowchart.

From Findings to Requirements

Data collection is useful only if evidence is converted into clear requirements.

Finding

Librarians spend too long searching several records to find active loans.

→

Requirement

The system should allow active loans to be searched by student ID.

Finding

Students often ask staff whether a book is currently available.

→

Requirement

The system should display the current availability of each book.

Finding

The school cannot replace all library computers.

→

Constraint

The solution should operate on existing school hardware where possible.

Comparing Alternative Solutions

Compare an existing library package with a bespoke system using the same feasibility criteria.

Feasibility	Question to Ask
Technical	Can it work with available hardware, software and skills?
Economic	Are costs acceptable relative to expected benefits?
Operational	Will it fit workflows and be accepted by users?
Time	Can it be implemented before the required deadline?

Option A — Existing Package

Option B — Bespoke System

Comparison ≠ Listing

A strong comparison links both alternatives using the same criterion. Example: “The package may be deployed sooner, whereas the bespoke system requires development and testing time.”

Cambridge-Style Justification

When asked to recommend a solution, use scenario evidence. A conclusion should follow from feasibility evidence rather than simply saying one option is “better”.

Common Pitfalls

Choosing a Method Without Justification

“Use an interview” is incomplete. Explain why it fits the stakeholder and information required.

Reported Workflow ≠ Actual Workflow

What users say and what happens in practice may differ. Observation can verify real working practice.

Writing Solutions Before Requirements

First identify problems and requirements. Only then compare possible solutions.

DFD ≠ Flowchart

A DFD shows movement of data; a program flowchart shows algorithmic control flow.

Cheapest ≠ Automatically Most Feasible

Cost is only one criterion. Technical, operational and time feasibility also matter.

Practice Tasks

Remember

Name five data collection methods and state one strength of each.

Understand

Explain the difference between an open and a closed question. Give one library-system example of each.

Apply

Choose an appropriate method to discover how librarians actually issue and return books. Justify your choice.

Apply

Design a five-question student questionnaire containing both open and closed questions.

Apply

Identify two inputs, two processes, two outputs and two data stores for an online cinema booking system.

Analyze

Turn this finding into a requirement: “Staff spend several minutes checking three files before approving a booking.”

Analyze

Compare an existing software package with a bespoke solution using all four feasibility criteria.

Create

Produce a mini analysis report for a school process: collection plan → analysis → two requirements → two alternatives.

Exam Practice

Q1: Describe two advantages of interviewing users when analysing an existing system. [4]

Reveal marking points

Information is obtained directly from experienced users; questions can be clarified or followed up; detailed responses can be obtained. Develop each point.

Q2: Explain why observation and document review may both be used to investigate the same system. [4]

Reveal marking points

Observation shows actual working practice in real time; document review reveals existing forms, records and documented procedures. Together they allow practice to be compared with recorded processes/data.

Q3: A school is replacing a paper booking system. State one input, one process, one output and one data store. [4]

Reveal marking points

Answers must fit the scenario. Example: input — booking date; process — check availability; output — confirmation; data store — bookings database.

Q4: Explain two feasibility criteria used when comparing alternative solutions. [4]

Reveal marking points

Any two of technical, economic, operational or time feasibility, each explained rather than only named.

Q5: Explain why an analyst should collect information before specifying requirements. [3]

Reveal marking points

The analyst must understand the current system and user problems; evidence identifies what must change; this reduces the risk of designing a system that does not meet needs.

Self-Check Quiz

Q1: Which collection method is best for detailed follow-up questions?

Interview.

Q2: Which method is useful for seeing how a process actually happens?

Observation.

Q3: What is the difference between open and closed questions?

Open questions allow detailed free responses; closed questions restrict answers to predefined choices.

Q4: Name the five analysis areas used on this page.

Inputs, processes, outputs, data stores and constraints.

Q5: What does a DFD show?

How data flows between external entities, processes and data stores.

Q6: What are the four feasibility criteria?

Technical, economic, operational and time feasibility.

Exit Ticket — 3–2–1

Name three data collection methods.

Give two things an analyst should identify in the current system.

Write one feasibility criterion and the question it asks.