Written practice

Context Diagram Scenario Practice

Write your response first, check it against the checklist, then reveal the model answer.

Task 1: Create a context diagram plan

Canteen Ordering System

Scenario

Students submit lunch orders to the canteen ordering system. The canteen manager receives order summaries. Suppliers receive stock requests and send delivery confirmations. Students receive order confirmations.

Your prompt

List the external entities and data flows you would use before drawing the context diagram.

Self-check

  • Central process names the whole system
  • External entities are outside the system
  • Every data flow has a clear noun phrase label
  • No internal database tables or screens are included

Task 2: Analyse and correct a diagram

Library Loan System

Scenario

A draft diagram shows Student sending a book request to Library Loan System, Library Loan System sending loan confirmation to Student, and Student sending overdue notice directly to Parent.

Your prompt

Explain what is wrong with the draft and how to correct it.

Self-check

  • Identifies any external-to-external data flow
  • Corrects the flow so it passes through the system
  • Keeps one system process
  • Uses clear data labels

Task 3: Document an existing system

Excursion Permission System

Scenario

Parents submit permission forms and medical information. Teachers receive approved student lists. The school office receives payment status reports.

Your prompt

Document the existing system before drawing: purpose, entities, inputs, and outputs.

Self-check

  • States the system purpose
  • Separates external entities from internal information
  • Lists inputs into the system
  • Lists outputs from the system