Slide 1

What makes up an information system?

Input

Process

Output

Temperature and rainfall from a variety of places

Analyse the information and present graphically

Web pages for holidaymakers to help them decide when and where to go

Slide 2

Input: Temperature, humidity, light

Process: Check the temperature and turn heater on/off

Output: Correct growing conditions, resulting in healthy plants

Greenhouse

Slide 3

Lighthouse

Input: Visibility

Process: Is visibility poor?

Output: Turn on fog horn

Slide 4

Washing machine

Input: Wash programme, water, washing powder

Process: Match amount of water, temperature to programme

Output: Clean washing

Slide 5

Security light

Input: Movement

Process: Is light below a predefined level?

Output: Turn on light

Slide 6

Pelican crossing

Input: Pedestrian presses walk button

Process: Has the set amount of time gone by?

Output: Activate the light sequence

Slide 7

What is a system?

A computer system ‘may include hardware, as well as software and manual procedures’.

BCS Glossary of computing terms

Slide 8

Today you will:

Review knowledge and understanding of systems

Slide 9

Making tea

Pour tea into cup

Put teabag in pot

Fill kettle

Add milk

Put the instructions in the right order.

Identify any instructions that are missing.

Slide 10

Start

Put tea in pot

Milk? Stop

Pour milk into cup

Boil water

Add water

No

Wait until brewed

YesMilk?

Pour milk into cupYes

Sugar?

No

Pour tea into cup

Yes

Add sugar

Making tea

Drink tea

Slide 11

Cooking a celebration lunch

Prepare main dish

Put main dish in oven

While main dish cooks, prepare vegetables

Put potatoes on to cook

Put vegetables on to cook

Arrange all times to coincide with main dish being ready

Lay table

IdentifyOutline of the problem

AnalyseThe needs of the system

EvaluateRefining the system

DesignPlanning all parts of the

system

ImplementCreating the system

TestMaking sure the system

works

System life cycle