What makes up an information system

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
2
Greenhouse
Input Temperature, humidity, light Process
Check the temperature and turn heater
on/off Output Correct growing conditions,
resulting in healthy plants
3
Lighthouse
Input Visibility Process Is visibility
poor? Output Turn on fog horn
4
Washing machine
Input Wash programme, water, washing
powder Process Match amount of water,
temperature to programme Output Clean washing
5
Security light
Input Movement Process Is light below a
predefined level? Output Turn on light
6
Pelican crossing
Input Pedestrian presses walk button Process
Has the set amount of time gone by? Output
Activate the light sequence
7
What is a system?

• A computer system may include hardware, as well
  as software and manual procedures.
• BCS Glossary of computing terms

8
Today you will

• Review knowledge and understanding of systems

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.
10
Making tea
Start
Pour tea into cup
Boil water
Yes
Put tea in pot
Sugar?
Add water
No
Add sugar
Wait until brewed
Drink tea
Pour milk into cup
Pour milk into cup
Yes
Yes
Milk?
Milk?
Stop
No
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

12
Identify Outline of the problem
Evaluate Refining the system
Analyse The needs of the system
System life cycle
Design Planning all parts of the system
Test Making sure the system works
Implement Creating the system