Standard Grade Computing

learnedmooseupvalleyElectronics - Devices

Nov 7, 2013 (3 years and 9 months ago)

67 views

Standard Grade Computing

Commercial Data Processing

Introduction

Commercial Data Processing deals with how
LARGE

companies and organisations use computers in their
businesses.

Examples

of large companies and organisations:



supermarkets (ASDA, Tesco, Morrisons)



chain stores (Currys, Comet, Argos)



banks (Royal Bank of Scotland, Clydesdale, Abbey)



airlines (British Airways, Ryanair, Qantas)



organisations (police, Inland Revenue, DVLA)

Mainframe Computer

Key facts

about a mainframe:

A large computer system that can process
huge amounts

of
data
accurately

and at
very high speeds

Has
hundreds

of

dumb terminals

attached to it

Has a
very large amount of RAM

(many Gigabytes)

Has
more than one

processor

Has a
huge backing storage capacity

(Gigabytes or Terabytes)

Need for CDP (1)

Volume of Documents



large companies and organisations
need to process a huge amount of data every day

Speed of processing



computers are ideal for accurate
processing of data at very high speeds. Human beings process
data slowly in comparison

Repetitive tasks



computers are great at performing the
same task over and over again without making mistakes.
Humans get tired and make mistakes when they do the same
task continuously

Need for CDP (2)

Management Information



computers process data and
turn it into information. Managers can use the information to
run their businesses more effectively

Example:

A supermarket manager might want to know how
many tins of
Heinz beans

were sold in a week and how
much money
(£££)

the company made from selling beans

Speed of Access



the data stored on a computer can be
found and accessed very quickly. Human beings
searching for data in paper based systems (eg filing
cabinets) takes much longer

Data Processing Cycle (1)

The
data processing cycle

is the order that data is processed in. The
data processing cycle is made up of
4
stages:

1.
Data collection and preparation

2.
Data input

3.
Data processing and storage

4.
Data output

Data Processing Cycle (2)

What is data?

Data are the numbers, symbols and characters that can be
processed by a computer. Data on its own has no meaning
to human beings.

What is information?

Information is data that has been processed by a computer
into a human readable format.

Examples of data:
01001110


.
-
.
-
.
--
.
-
.
-
.
---

--
.
-
.

2532302822

Examples of information:
£25 12 January 2006 25
0
Centigrade

Data Processing Cycle (3)

This piece of data:

30

6

9

03

becomes

30 March 1969

when processed into information by a computer

Information (for people) =

data (for computers)

+ meaning

Data Collection and
Preparation

Data can be collected in many different ways. If data is written
down or printed on a piece of paper, that piece of paper is called a
source document
.

An order form for a catalogue is an
example of a source document.

Data Input (1)

Data needs to be input into the computer
BEFORE

it can be
processed. Inputting data directly into a computer means that
fewer mistakes will be made.

Here are some ways of inputting data into a computer:



bar codes



mark sense cards



magnetic stripes



magnetic ink character recognition (MICR)



optical character recognition (OCR)



smart cards

Data Input (2)

Can be found on books, groceries, newspapers etc

Made up of
black

and
white

vertical bars that hold coded
information

Coded information is read by reflected laser light

The
4

pieces of coded information
on a bar code are:

country of origin

manufacturer

product

check digit

Bar Codes

5

012345

678956

Data Input (3)

……………………………………………………….

……………………………………………………….

Mark sense cards

Name:

Joe Bloggs

WARD:

2a

Ayrshire General
Hospital

Lunch

Menu

]
TO CHOOSE

DIET

EXTEND THE BAR TO THE BRACKET

1 Scotch Broth

2 Chicken Soup

3 Orange Juice

4 Poached Haddock in Milk

5 Chicken Curry

6 Ham Salad

7 Jelly and Ice Cream

8 Trifle

9 Apple Pie

]

]

]

]

]

]

]

]

]

Marks are made on cards
that can be read by special
card reading equipment

Mark cards can be used in
multiple choice exams and
to choose your food when
you are in hospital

Data Input (4)

Magnetic stripes

Signature

J Bloggs

A magnetic stripe is a narrow band
of magnetic material on which data
is held

Can be seen on the back of
credit
cards
,
bank card

and
train tickets

Stores information like
sort codes

and
account numbers

Data Input (5)

Second Direct

Platinum

Credit Card

675940 00001234567

VISA

VALID

FROM

01/06

EXPIRES

END

06/08

Miss Jane Bloggs

Smart Cards

These cards can be used as bank
cards, credit cards, store cards and
identity cards

They can store personal
information and hold digital cash

More secure than magnetic stripe
cards because they are difficult to
forge.

They have a
microchip
that can
hold and process information

Data Input (6)

Magnetic Ink Character Recognition
(MICR)

Is the process where characters
are printed on forms in
magnetic ink

People and computers can read
the characters

When a cheque is paid into a bank a magnetic ink
character reader is used to input the information
into a computer

Data Input (7)

Optical Character Recognition (OCR)

UK GAS

MR J RAE

Customer Ref. No.

216 024 4567

Date

Meter Reading

Gas Supplied

Charges

31 JAN

Present

Previous

1878

1502

376

100’s
cu

ft

Therms

397.432

182.42

9.40

STANDING CHARGE

£ 191.82

CREDIT TARIFF

BANK PAY

Customer Ref. No.

Customer Acc. No.

Amount Due

216 024 4567

118 3467


£ 191.82

Cashier’s Stamp and initials

Cash

Cheques

Total
£

Signature

Please do not write or mark below this line or fold this counterfoil

191825 2160244567 00 2160244567 00191825

A device called an
optical

character reader

is able to
recognise letters and numbers
(eg
ABC

or
1234
) and read
them directly into a computer

An OCR system
CAN’T

read
letters or numbers that have
been printed badly

Data Input (8)

Validation

is a pre
-
input check on data to make sure that it is
sensible
and

accurate

Examples:

Check Digit

Length Check

Range Check

Verification
involves using two different human operators to enter
the same data. The computer compares both sets of data that have
been entered and, if it finds a mistake, both sets of data must be
entered again

Data Input (9)

A
check digit

is an extra digit that is calculated from an original
number and is then put on the end of the number.

Example

: let’s make up a check digit for the number

So the check digit is a

To make the total divide exactly by three, we
MUST

add an extra
digit (in this case a
1
) at the end of the number to make the total
21
.
This is because 21 divides exactly by three

We add all the digits together


Adding the check digit to the original number gives

2954

2 + 9 + 5 + 4 = 20

29541

1

Data Input (10)

Length Check

This

involves checking the

number of

characters

(numbers,
letters and spaces) entered into a computer. If too many or too
few characters are entered then an error message will be
displayed

Only dates with
exactly 8 characters

(eg
30031969
) are valid

Example
A date needs to be entered into the computer in the
format

ddmmyyyy


which is 8 characters long

If you made a mistake and typed in

303031969

the computer would not accept the data and give an error
message

Data Input (11)

Range Check

A range check can be made on numeric data like ages, money and
test marks to check that the numbers are sensible and in the
correct range

Examples:

A valid age range for secondary
school pupils should be between
11

and
18

In Higher Computing a valid
range of marks for a test is
between
0

and
20

Data Processing and Storage (1)

File



is an organised collection of structured data on the same topic.
The units that make up a file are records.

Record



is an organised collection of structured data on a person
or thing (
entity
). A record is like a single card in a card index.

Field



a single piece of information that appears on a record.

Name

Job Title

Employee No

Salary

001

Systems Analyst

Ian Wright

£40,000

record

field

file

Data Processing and Storage (2)

Backup


this is a
copy

of your original data file



A backup is needed in case the original data file is

accidentally or deliberately lost



There should be more than one backup copy of a

file



Backup copies

should be

stored in a

fireproof safe

for extra security

Original file stored
on hard disk

Backup copy stored on a
separate hard disk

Data Processing and Storage (3)

Update


this means adding new data or making changes
to old data that is already stored in a data file

Example:

Ian Wright gets a salary increase from £40,000
per year to £50,000 per year. This means that his record in
the employee data file needs to be updated:

Name

Job Title

Employee No

Salary

001

Systems Analyst

Ian Wright

£40,000

old record

Name

Job Title

Employee No

Salary

001

Systems Analyst

Ian Wright

£50,000

new record

Data Processing and Storage (4)

File access methods

Sequential access
is used to store data files on magnetic tape

The records in the data file are stored

one after the other

To access a particular record the computer would have to go
through all the records in sequence from the beginning until it was
found

Employee No

Job Title

Name

Salary

001

£40,000

Ian Wright

Systems Analyst

Employee No

002

Job Title

Name

Salary

£35,000

Programmer

Laura Wood

Employee No

003

Job Title

Data Input Clerk

Name

Cameron Rae

Salary

£15,000

Employee No

004

Job Title

Computer Operator

Name

Helen Black

Salary

£27,000

Magnetic tape

Direction of Search


Data Processing and Storage (5)

Direct/Random access
data files stored for direct access can be
read directly without having to work through all the records
from the beginning

Magnetic disks

and
optical disks

are two
examples of direct access media

Interactive processing
is when data is processed or updated as
a transaction is entered and any queries are replied to at once

Examples

:
booking holidays and
automated teller machines (ATM’s)

Data Processing and Storage (6)

Multi
-
user database


this is a database on a network that can
be accessed by many users at the same time

To allow multi
-
user access the database file must be stored
centrally on either a mainframe computer or a file server

Example



when lots of people can access their bank’s account
database at the same time

Bank account details stored
in a database on a mainframe
computer in
Edinburgh

ATM in
Kilmarnock

ATM in
Ayr

ATM in
Glasgow

ATM in
Aberdeen

Data Output

Output to Paper



print
-
outs are created for staff and
customers. High speed printers are used to create the print
-
outs

Examples



bank account statements,
electricity and gas bills and wage slips

Output to Screen



screen output is used to allow the computer
to communicate with the operator


Output to file



output can be saved as a new file for
processing later. The new file would be stored on tape or disk.

Social Implications (1)

Job losses

because computers have replaced people doing
traditional jobs (eg typists)

Retraining



workers that are left need to be trained how to
operate, program and maintain the computer system(s)

Effects on business


companies will enjoy

higher
productivity and higher profits

Social Implications (2)

Job types and careers:

Programmer



designs, writes and tests the programs that
process all the data

Engineer



maintains the computer system(s) and repairs
them if they break down

Network manager



is the person in overall charge of the
network

Systems Analyst



looks at manual or legacy systems and
decides on the hardware and software to be used by a
company

Social Implications (3)

Computer crime:

Computer viruses

are rogue programs
that replicate
themselves and can
destroy and corrupt
data

Hacking

involves
illegally breaking
into a computer
system. If data is
damaged it is called
cracking

Computer Fraud

normally involves
stealing money
electronically

Computer Misuse Act
is a law that tries to
prevent these crimes
from happening

Technical Implications (1)

E
-
commerce


is the process of buying and selling goods and
services on the Internet

Examples
:

www.churchill.com (insurance)

www.pcworld.co.uk

Technical Implications (2)

On
-
line shopping


is another name for e
-
commerce

Involves visiting a web site and using a
shopping basket

to
store the items you have selected and want to buy

When the purchase is complete the web site will send an e
-
mail
to confirm the order has been placed

How do you pay for on
-
line shopping?

Credit cards

(
Visa

and

Mastercard
)

Debit cards (
Switch

and

Delta
)

Technical Implications (3)

Advantages of on
-
line shopping:

For companies
-

selling on the Internet is cheaper than selling
on the high street

Customers can shop 24 hours a day from the comfort of their
own home

Disadvantages of on
-
line shopping:

Fraud can take place when a credit or debit card is stolen and
the number on it is used to buy something on the net


this type
of activity is called
card not present
fraud

A customer may not be at home when the goods are delivered

Technical Implications (4)

On
-
line banking


is the process of accessing your bank
account and carrying out transactions on the Internet (eg pay
bills and move money)

Involves logging into a secure web site (small padlock should
be at the bottom of the screen)

Customer must enter a
User ID

and
Password

to enter the site

Advantage



on
-
line banks
DO NOT

need to have
branches in the High Street
which saves the bank money

Disdvantage



the service can
be impersonal (ie no face to
face contact with a person)

Technical Implications (5)

Electronic Funds Transfer (EFT)

This is where you pay for goods and services without using
cash

When you buy something, the money that you owe the shop
is transferred electronically from your bank account into the
shops bank account

You need to have a bank card that supports this type of
payment

Your banks computer

The shops computer

Technical Implications (6)

Point of Sale (POS)

POS
is the name given to to a computerised system that
collects data automatically from the checkout, or point of sale,
as the customer buys goods

At the checkout a scanner reads the unique bar code on the item
that has been sold

The product code for the item is then sent to the till which is
connected to a computer that recognises all the product codes
for items in the shop

The till, using information from the computer, can then display
the name and price of the product

Economic Implications (1)

Initial costs
are the costs (amounts of money) involved in
buying the equipment needed to computerise a large business


Examples:

Hardware



computers, printers, bar code readers

Software



operating systems, application packages,
bespoke software

Economic Implications (2)

Running costs
are the costs (amounts of money) involved in
keeping the system operational day in and day out


Examples:

Electricity

Paper

Toner and ink

Security and Privacy
Implications (1)

Accuracy of information and privacy

A principal of the
Data Protection Act

is that information must
be
accurate

and
up to date

Large companies hold data about employees and customers

Companies must register with the

Information

Commissioner

who is responsible for the
Data Protection

Act

Information held in a computer data file must be kept
private
.
Information about how much someone earns or how much
credit they have been given
SHOULD NOT

be shown to
anyone else

Security and Privacy
Implications (2)

Physical security

Computers and data files cab be kept secure by:

Locking doors



a swipe card and/or pin number may have to
be used to enter the computer room

Locking keyboards



some keyboards can be locked so that
they can’t be used by unauthorised people

Security and Privacy
Implications (3)

Software security

Passwords


a password should not appear on the screen
(eg ******** ) and should be changed regularly

Encryption


this means to turn information into a code to
prevent it from being read by unauthorised users

Example:

how are you

Encryption
Software

krz duh brx

Security and Privacy
Implications (4)

Sale of customer lists

Some companies sell their lists of customer names and
addresses to other companies to make money

This is why we get so much junk mail nowadays

NOTE



you have the right to stop your name being used in
this way

Advantages (1)

Comparison with a manual system

A computerised CDP system has the following advantages:



accuracy


less likely to make mistakes/processes

data more accurately than people



speed


data is processed more quickly using

computers



volume of documents


computers can handle a

larger number of documents than people

Advantages (2)

Single entry multiple use

This means data is entered
once

into the computer and can
then be accessed for a number of different uses within an
organisation

Example


a new salesman gets a job for a big company and his
details are entered into the computer. Different departments can
now access and use the data.

Employee details
entered

sales dept

wages dept

personnel
dept

Questions (1)

1

Give
four

types of companies and
two

organisations that use CDP.

2

Give
four

facts that you know about a mainframe computer.

3

Briefly describe
four

reasons why companies use computers to process their data.

4

List the
four

stages that make up the data processing cycle.

5

(a)

What is the difference between
data

and
information
?

(b)

Give an example to support your answer.

6

Turn the following dates into data codes

31 March 1931

25 December 1999

15 October 1976

Questions (2)

7

(a) What is a
bar code
?


(b) What
four

pieces of coded information can be found from a bar code?

8

(a) What is a
mark sense card
?


(b) What
three

items did Joe Bloggs choose to eat when in hospital?

9

What is a
magnetic stripe
?

10

What is a
smart card
?

11

What is meant by the term
Magnetic Ink Character Recognition
?

12

What is meant by the term
Optical Character Recognition
?

13

What is meant by the term
validation
?

Questions (3)

14

Give
three

types of validation that can be performed on data

15

What is meant by the term
verification
?

16

What is a
check digit
?

17

What is a
length check
?

18

What is a
range check
?

19

What is:

(a)

a
file

(b)

a
record

(c)

a
field

20

Why is it a good idea to keep a
backup

of your original data file?

Questions (4)

21

What does the term
update

mean?

22

What is meant by the term
sequential access
?

23

Give
one

disadvantage of sequential access

24

What is meant by the term
direct access
?

25

Give
one

advantage that direct access has over sequential access.

26

What is meant by the term
interactive processing
?

27

What is a
multi
-
user database
?

Questions (5)

28

Briefly describe
three

ways in which information can be output from a computer.

29

Briefly describe the following job types and careers:


Programmer


Engineer


Network manager


Systems analyst

30

Give
three

examples of computer crime.

31

Name the law that tries to prevent computer crimes from happening.

32

What is
e
-
commerce
?

33

Explain what happens when you go
on
-
line shopping
?

34

Give
one advantage

and
one disadvantage

of on
-
line shopping.

Questions (6)

35

What is
on
-
line banking
?

36

Give
one advantage

and
one disadvantage

of on
-
line banking

37

Describe how
Electronic Funds Transfer

works.

38

What is meant by the term
Point Of Sale
?

39

Identify some of the
initial costs

involved in computerising a large business.

40

Identify some of the
running costs

involved in computerising a large business.

41

Give
two

types of
physical security

used to keep computers and data files safe.

Questions (7)

42

Give
two

types of
software security

used to keep computers and data files safe.

43

What is meant by the term
sale of customer lists
?

44

Give
three
advantages that a computerised CDP system has over a manual system.

45

What is meant by the term
single entry multiple use
?

THE END (phew!!!)