IGCSE ICT

Stock Control

U nderstand the need for and use ofautomated stock control systems

Be able to discuss the advantages and disadvantages of automated stock

control systemsUnderstand the role of the check

digit as a form of validation

The syllabus says you must:

Stock control : the old way

Price labels were handwritten and stuck on manually

Staff/time/costLabels could be

misread/changedYearly stock-check:

closed for business

The problems

SlowCostlyRequired many staff Impact on revenueAccuracy?Lost revenue through

wrong or misread labelsLost revenue through

stock-taking closures Stock control done by

guesswork

The technology behind ASCS

ASCS rely on barcodesBarcodes allow quick identification of

product details when the barcode is scanned

The barcode reader scans the barcode using a laser

It retrieves the price and the details from the database

What’s in a bar code? 1

Bar codes are made of alternating dark and light lines of varying thickness

What’s in a bar code? 2

The barcode contains data about the type of product, size, manufacturer and the country of origin. 

It also contains a check digit, so that the computer can validate that the data has been read in correctly.

What’s in a bar code? 3

The barcode does not contain price . The price is held in the database instead .

This makes it easy to change if there are special offers or prices go up . Imagine if the price was part of the barcode . Every time the price changed, you would have to replace all of the packaging .

What’s in a bar code? 4

Once the barcode has been recognized by the database and the price found, the data is sent from the central computer to the till (Electronic Point of Sale - EPOS).

The check digit

The check digit is a form of validation It is used to ensure no errors occurred

when the barcode was read inThere are a number of ways of

calculating check digits depending on how many digits there are in the barcode

This method works for codes with 11 digits:

Add the digits in the odd positions, multiply by 3(5+0+3+1+0+7=16 16x3=48)

Add the digits in the even position: 1+4+1+2+1=9

Add the two together: 48 + 9 = 57 Check digit is 3 (needs to be added to make next

multiple of 10). Checked every time a bar is scanned!

5 1 0 4 3 1 1 2 0 1 7

2 1 4 4 6 1 88 10 even digit positions

1 1 3 4 5 1 7 2 9 1 11 odd digit positions

Where are bar codes used?

Library book systemsAdministration systems (eg

hospitals)Passport & ID card systemsEquipment checking systems (eg fire

extinguishers)Automatic stock control systems

Sequence of events 1

1. Barcodes on all items: each is associated with a stock file holding details of price, stock level, description etc.

2. Customer goes to checkout: barcodes scanned

3. Stock file is searched, record by record, until a match is found

4. Appropriate record is accessed5. Price & description sent to EPOS6. Stock level reduced by 1: new stock level

written to file

Sequence of events 2

If new stock level is = or 1 less than re-order quantity, new batch is automatically ordered

Flag assigned to item to indicate order (stops re-order being made for EVERY purchase!)

This is repeated for every item in basket/trolley

Itemized bill given to customer Loyalty card updated/takings file updated Barcodes on cartons of new goods used to

update stock file & flags removed

Advantages & Disadvantages

Advantages Accuracy Speed Optimum stock levels Patient safety Equipment safety Analysis Automatic re-

ordering Automatic scheduling

of updates etc

Disadvantages Cost Training Over-reliance on

technology

Today’s assignment:

Download the file Electronic Fund Transfer Simulation

Enter some purchases and look carefully at the following: Banking/EFTPOS data Stock levels Receipt

Read the information at http://

communication.howstuffworks.com/how-

inventory-management-systems-work.htm

Homework

Go to www.edmodo.com and complete the homework assignment.