Context diagram (Level 0): data flows

Name:

Date:

Class:

Quick Questions

Shade in the A or B circle for each question.

1. On a context diagram, what does an arrow between an entity and the system represent?

A Data passing between the entity and the system

B A physical delivery of hardware to the system

2. A student submits an enrolment form to a school system. Which way should the arrowhead point?

A From the system towards the Student entity

B From the Student entity towards the system

3. A system sends a receipt to a customer. Which statement is correct?

A It is an output, so the arrow points to the Customer entity

B It is an input, so the arrow points to the system

4. Which is the better label for a data flow?

A Booking request

B Sends stuff

5. A data flow on a context diagram should be labelled with:

A The name of the programming language used

B The name of the data being passed

Match the Pairs

Draw a line connecting each item on the left to its match on the right.

Left column		Right column
1Student --> [Library System] : Loan request		AAn input data flow: the arrow points from the entity into the system, labelled with the data being sent (Loan request).
2[Library System] --> Student : Due date notice		BTeacher --> [Marks System] : Student marks [Marks System] --> Teacher : Class report
3Each data flow on a context diagram needs a label that names the specific data being passed, not just a vague word like 'info'.		CAn output data flow: the arrow points from the system out to the entity, labelled with the data being sent (Due date notice).
4Data flows between an entity and the system can go in both directions, so each direction is drawn as its own labelled arrow.		DThe line has no arrowhead and no label, so it shows neither the direction of the data nor what data is passing.
5Customer --- [Online Shop]		ECustomer --> [Online Shop] : Order details
6[Online Shop] --> Customer : Order details		FThe arrow direction is wrong. Order details are sent by the customer into the system, so the arrow should point from Customer to the system.

Definitions

data flow

Fill in the Blanks

Complete each line of code by filling in the missing parts.

Customer __ System : order details

______ -> Customer : receipt

Customer -> System : order details // _____

System -> Customer : receipt // ______

Customer -> System : order details System -> ________ : receipt

Spot the Error

Shade in the letter of the line that contains an error.

Question 1

A Context: Library System

B Member -> System: Loan form

C Staff -> System: Book details

D Member -> System: Due date

Question 2

A Context: Canteen System

B Student -> System: Order

C System -> Student

D Staff -> System: Menu update

Question 3

A Context: Member

B Member -> System: Booking

C System -> Member: Timetable

Question 4

A Context: Tuckshop System

B Student -> System: Order

C System -> Kitchen: Data

D Kitchen -> System: Stock list

Question 5

A Context: Banking App

B Customer -> Bank: Transfer

C Bank -> System: Approval

D System -> Customer: Balance

Answer Key

Context diagram (Level 0): data flows

Section A: Quick Questions

A — Data passing between the entity and the system

B — From the Student entity towards the system

A — It is an output, so the arrow points to the Customer entity

A — Booking request

B — The name of the data being passed

Section B: Match the Pairs

Student --> [Library System] : Loan request → An input data flow: the arrow points from the entity into the system, labelled with the data being sent (Loan request).

[Library System] --> Student : Due date notice → An output data flow: the arrow points from the system out to the entity, labelled with the data being sent (Due date notice).

Each data flow on a context diagram needs a label that names the specific data being passed, not just a vague word like 'info'. → Customer --> [Online Shop] : Order details

Data flows between an entity and the system can go in both directions, so each direction is drawn as its own labelled arrow. → Teacher --> [Marks System] : Student marks [Marks System] --> Teacher : Class report

Customer --- [Online Shop] → The line has no arrowhead and no label, so it shows neither the direction of the data nor what data is passing.

[Online Shop] --> Customer : Order details → The arrow direction is wrong. Order details are sent by the customer into the system, so the arrow should point from Customer to the system.

Section C: Definitions

data flow — A labelled arrow on a context diagram showing data passing between an entity and the system. The arrowhead shows direction (input or output) and the label names the data.

Section D: Fill in the Blanks

Customer -> System : order details

System -> Customer : receipt

Customer -> System : order details // input

System -> Customer : receipt // output

Customer -> System : order details
System -> Customer : receipt

Section E: Spot the Error

D — The arrow direction is wrong. The due date is an output from the system to the member, so the arrowhead should point to Member: System -> Member: Due date.

C — Every data flow arrow must be labelled with the data it carries. This arrow needs a name, such as System -> Student: Receipt.

A — The single central shape on a context diagram is the system, not an entity. It should read Context: Gym Booking System, with Member as an external entity sending and receiving flows.

C — A data flow label must name the specific data being passed. 'Data' is too vague; it should be something like Order list.

B — Data flows on a context diagram go between an entity and the system, never directly between two entities. The flow should be Customer -> System: Transfer.